The Otto Aufranc Award: Does Hip Arthroscopy at the Time of Periacetabular Osteotomy Improve the Clinical Outcome for the Treatment of Hip Dysplasia? A Multicenter Randomized Clinical Trial.

BACKGROUND: A periacetabular osteotomy (PAO) is often sufficient to treat the symptoms and improve quality of life for symptomatic hip dysplasia. However, acetabular cartilage and labral pathologies are very commonly present, and there is a lack of evidence examining the benefits of adjunct arthroscopy to treat these. The goal of this study was to compare the clinical outcome of patients undergoing PAO with and without arthroscopy, with the primary end point being the International Hip Outcome Tool-33 at 1 year. METHODS: In a multicenter study, 203 patients who had symptomatic hip dysplasia were randomized: 97 patients undergoing an isolated PAO (mean age 27 years [range, 16 to 44]; mean body mass index of 25.1 [range, 18.3 to 37.2]; 86% women) and 91 patients undergoing PAO who had an arthroscopy (mean age 27 years [range, 16 to 49]; mean body mass index of 25.1 [17.5 to 25.1]; 90% women). RESULTS: At a mean follow-up of 2.3 years (range, 1 to 5), all patients exhibited improvements in their functional score, with no significant differences between PAO plus arthroscopy versus PAO alone at 12 months postsurgery on all scores: preoperative International Hip Outcome Tool-33 score of 31.2 (standard deviation [SD] 16.0) versus 36.4 (SD 15.9), and 12 months postoperative score of 72.4 (SD 23.4) versus 73.7 (SD 22.6). The preoperative Hip disability and Osteoarthritis Outcome pain score was 60.3 (SD 19.6) versus 66.1 (SD 20.0) and 12 months postoperative 88.2 (SD 15.8) versus 88.4 (SD 18.3). The mean preoperative physical health Patient-Reported Outcomes Measurement Information System score was 42.5 (SD 8.0) versus 44.2 (SD 8.8) and 12 months postoperative 48.7 (SD 8.5) versus 52.0 (SD 10.6). There were 4 patients with PAO without arthroscopy who required an arthroscopy later to resolve persistent symptoms, and 1 patient from the PAO plus arthroscopy group required an additional arthroscopy. CONCLUSIONS: This randomized controlled trial has failed to show any significant clinical benefit in performing hip arthroscopy at the time of the PAO at 1-year follow-up. Longer follow-up will be required to determine if hip arthroscopy provides added value to a PAO for symptomatic hip dysplasia.

What Is the Correlation Among dGEMRIC, T1p, and T2* Quantitative MRI Cartilage Mapping Techniques in Developmental Hip Dysplasia?

BACKGROUND: Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a validated technique for evaluating cartilage health in developmental dysplasia of the hip (DDH), which can be a helpful prognosticator for the response to surgical treatments. dGEMRIC requires intravenous injection of gadolinium contrast, however, which adds time, expense, and possible adverse reactions to the imaging procedure. Newer MRI cartilage mapping techniques such as T1 rho (ρ) and T2* have been performed in the hip without the need for any contrast, although it is unknown whether they are equivalent to dGEMRIC. QUESTION/PURPOSE: In this study, our purpose was to determine the correlation between the relaxation values of three cartilage mapping techniques, dGEMRIC, T1ρ, and T2*, in patients with DDH. METHODS: Fifteen patients with DDH (three male, 12 female; mean age 29 ± 9 years) scheduled for periacetabular osteotomy underwent preoperative dGEMRIC, T1ρ, and T2* MRI at 3T with quantitative cartilage mapping. The outcomes of dGEMRIC, T1ρ, and T2* mapping were calculated for three regions of interest (ROI) to analyze the weightbearing cartilage of the hip: global ROI, anterior and posterior ROI, and further subdivided into medial, intermediate, and lateral to generate six smaller ROIs. The correlation between the respective relaxation time values was evaluated using the Spearman correlation coefficient (rS) for each ROI, categorized as negligible, weak, moderate, strong, or very strong. The relaxation values within the subdivided ROIs were compared for each of the three cartilage mapping techniques using the Kruskal-Wallis test. RESULTS: There was a moderate correlation of T1ρ and T2* relaxation values with dGEMRIC relaxation values. For the global ROI, there was a moderate correlation between dGEMRIC and T2* (moderate; rS = 0.63; p = 0.01). For the anterior ROI, a moderate or strong correlation was found between dGEMRIC and both T1ρ and T2*: dGEMRIC and T1ρ (strong; rS = -0.71; p = 0.003) and dGEMRIC and T2* (moderate; rS = 0.69; p = 0.004). There were no correlations for the posterior ROI. The mean dGEMRIC, T1ρ, and T2* relaxation values were not different between the anterior and posterior ROIs nor between the subdivided six ROIs. CONCLUSION: Quantitative T1ρ and T2* cartilage mapping demonstrated a moderate correlation with dGEMRIC, anteriorly and globally, respectively. However, the clinical relevance of such a correlation remains unclear. Further research investigating the correlation of these two noncontrast techniques with clinical function and outcome scores is needed before broad implementation in the preoperative investigation of DDH. LEVEL OF EVIDENCE: Level II, diagnostic study.

Hip Joint Preservation Surgery: What Every Orthopaedic Provider Needs to Know.

The understanding of the native hip's mechanics, physiology, and pathology has dramatically improved over the recent 2 decades. This was facilitated by the introduction of open and arthroscopic procedures to the native hip aimed at improving the joint's function and longevity. Associations between abnormal hip mechanics and further development of osteoarthritis are now clear. As the knowledge of hip joint mechanics has improved, other conditions around the hip have become evident, which may lead to pain but not necessarily osteoarthritis. It is important for the orthopaedic surgeon to be up to date on how the hip preservation field has evolved and the steps to consider when a painful hip presents in clinic.

Femoroacetabular Impingement: What the Surgeon Wants to Know.

Femoroacetabular impingement (FAI) is increasingly recognized as a risk factor for early hip degeneration in young active patients. The diagnosis depends on clinical examination and proper imaging that should be able to identify abnormal and sometimes subtle morphological changes. Labral tears and cartilage lesions rarely occur without underlying bone abnormalities. Surgical approaches to treat FAI are increasing significantly worldwide, even without a clearly defined consensus of what should be accepted as the standard imaging diagnosis for FAI morphology.Hip abnormalities encompass many variations related to the shape, size, and spatial orientation of both sides of the joint and can be difficult to characterize if adequate imaging is not available.This article presents a comprehensive review about the information orthopaedic surgeons need to know from radiologists to plan the most rational approach to a painful hip resulting from a mechanical abnormality.

A Contemporary Definition of Hip Dysplasia and Structural Instability: Toward a Comprehensive Classification for Acetabular Dysplasia.

Hip dysplasia has long been known to be a risk factor for pain and degenerative changes in the hip joint. The diagnosis of dysplasia has historically been based on assessments of acetabular anatomy on the anteroposterior pelvic radiograph, most commonly the lateral center-edge angle. Recent advances in imaging of the dysplastic hip with computerized tomography scans have demonstrated that hip dysplasia is in fact a 3-dimensional (D) deformity of the acetabulum and that multiple patterns of hip instability exist that may not be completely assessed on 2D imaging. A more thorough understanding of acetabular anatomy permits an evolution away from vague terms such as "borderline dysplasia." A 3D assessment of the acetabulum and the resultant patterns of instability may be more appropriate since this would allow more accurate treatment to correct the structural instability with acetabular reorientation. With this information, we propose a diagnostic framework that groups symptomatic dysplastic hips into one of 3 categories based on the primary direction of instability: (1) anterior, (2) posterior, and (3) global. This framework may aid the clinician in developing a differential diagnosis for the assessment of hip pain and suspected instability, and for planning an appropriate surgical management.

Dual mini-fragment plating for midshaft clavicle fractures: a clinical and biomechanical investigation.

BACKGROUND: We sought to evaluate clinical and biomechanical outcomes of dual mini-fragment plate fixation for clavicle fractures. We hypothesized that this technique would produce an anatomical reduction with good clinical outcomes, be well tolerated by patients, and demonstrate equivalent biomechanics to single plating. METHODS: Dual mini-fragment plating was performed for 17 isolated, displaced midshaft clavicle fractures. Functional outcomes and complications were retrospectively reviewed. A sawbones model compared dual plating biomechanics to a (1) superior 3.5-mm locking reconstruction plate, or (2) antero-inferior 3.5-mm locking reconstruction plate. RESULTS: On biomechanical testing, with anterior loading, dual plating was significantly more rigid than single locked anterior-plating (p = 0.02) but less rigid than single locked superior-plating (p = 0.001). With superior loading, dual plating trended toward higher rigidity versus single locked superior-plating (p = 0.07) but was less rigid than single locked anterior-plating (p = 0.03). No statistically significant differences in axial loading (p = 0.27) or torsion (p = 0.23) were detected. Average patient follow-up was 16.1 months (12-38). Anatomic reduction was achieved and maintained through final healing (average 14.7 weeks). No patient underwent hardware removal. Average 1-year DASH score was 4.0 (completed in 88 %). CONCLUSIONS: Displaced midshaft clavicle fractures can be effectively managed with dual mini-fragment plating. This technique results in high union rates and excellent clinical outcomes. Compared to single plating, dual plating is biomechanically equivalent in axial loading and torsion, yet offers better multi-planar bending stiffness despite the use of smaller plates. This technique may decrease the need for secondary surgery due to implant prominence and may aid in fracture reduction by buttressing butterfly fragments in two planes.

Comparing the rates and modes of failure of two third generation cephalomedullary nail systems in the treatment of intertrochanteric hip fractures.

INTRODUCTION: Cephalomedullary (CMN) implants are commonly used to address elderly intertrochanteric hip fractures. Multiple CMN implant systems exist with subtle variation between manufacturers. Multiple modes of CMN failure have been described in the literature. The present study assessed the local modes and rates of construct failure (nail fracture, cut-out and non-union) of two such implants, after a change in implant supply provided the opportunity for retrospective comparison. Additional investigation was undertaken to assess whether any predictors of failure could be identified based on common radiographic measurement parameters. METHODS: Based on local implant records, all consecutive patients who suffered an intertrochanteric fracture, treated at a tertiary care hospital with a cephalomedullary nail from January 2014 to January 2018 were included. Patients were excluded if they received a CMN for pathologic fracture. Within the collection period all patients received either a Synthes Trochanteric Fixation Nail (TFN) or Zimmer Natural Nail (ZNN). Patients were retrospectively assessed for fracture reduction and implant technique parameters at the time of initial surgery. Radiographic data were assessed at minimum two years post-operatively to assess for union. Patient demographic data was followed to assess rate and mode of failure. RESULTS: Six hundred and sixty-two patients were included in the study, from which a propensity matched cohort was derived. Comparing across equivalent cohorts, no differences in the rate or mode of construct failure were identified between the TFN and ZNN. When assessing the entire cohort we observed 39 construct failures (5.9%), which included 31 instances of nail cutout (4.7%), 4 episodes of nail fracture (0.6%) and 4 failures related to non-union (0.6%). Tip to apex distance, sagittal malalignment and Cleveland zone were identified as significant predictors of nail failure. CONCLUSION: No difference in rates or modes of failure were identified between the TFN and ZNN constructs. Similar to previous reports we again identified the impact of tip to apex distance on construct failure and further identified Cleveland zone and sagittal malalignment as significant risks for failure.

Outcome After Open Reduction Internal Fixation of Acetabular Fractures in the Elderly.

OBJECTIVES: (1) Assess outcomes of acetabular open reduction and internal fixation (ORIF) in the elderly, (2) investigate factors influencing outcome, and (3) compare outcomes after low-energy and high-energy mechanisms of injury. DESIGN: Retrospective case series. SETTING: Level 1 trauma center. PATIENTS: Seventy-eight patients older than 60 years (age: 70.1 ± 7.4; 73.1% males). INTERVENTION: ORIF for acetabular fractures. MAIN OUTCOME MEASUREMENTS: Complications, reoperation rates, Oxford Hip Score (OHS), and joint preservation and development of symptomatic osteoarthritis. Cases with osteoarthritis, OHS < 34, and those who required subsequent total hip arthroplasty were considered as poor outcome. RESULTS: At a mean follow-up of 4.3 ± 3.7 years, 11 cases post-ORIF required a total hip arthroplasty. The 7-year joint survival post-ORIF was 80.7 ± 5.7%. Considering poor outcome as failure, the 7-year joint survival was 67.0 ± 8.9%. The grade of reduction was the most significant factor associated with outcome post-ORIF. Female sex (P = 0.03), pre-existing osteoporosis (P = 0.03), low-energy trauma (P = 0.04), and Matta grade (P = 0.002) were associated with poor outcome. Patients with associated both-column fractures were more likely to have nonanatomic reduction (P = 0.008). After low-energy trauma, joint survivorship was 36.6 ± 13.5% at 7 years compared with 75.4 ± 7.4% in the high-energy group when considering poor outcome as an end point (log rank P = 0.006). The cohort's mean OHS was 37.9 ± 9.3 (17-48). CONCLUSIONS: We recommend ORIF whenever an anatomic reduction is feasible. However, achievement and maintenance of anatomic reduction are a challenge in the elderly, specifically in those with low-energy fractures involving both columns, prompting consideration for alternative management strategies. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Patellar Fractures: Anatomy, Mechanics, and Surgical Management.

➤: A preoperative computed tomography scan may be considered to improve surgical planning, as secondary fracture lines are poorly visualized on radiographs. ➤: Oblique internal and external rotation fluoroscopic views may be used intraoperatively to fully evaluate the medial and lateral facet articular reduction if direct assessment by visualization or palpation is not completed. ➤: Partial patellectomy for inferior pole fractures should be avoided, and bone-preserving procedures are recommended. ➤: A lateral arthrotomy may be used for direct visualization of the articular reduction for multifragmentary fractures. An inferomedial arthrotomy should be avoided to protect the dominant blood supply of the patella. ➤: Tension band fixation with cannulated screws yields a lower reoperation rate, improved functional outcome scores, and better performance in biomechanical studies than Kirschner wire-based tension band fixation. ➤: Preliminary studies of novel plate and screw constructs for osteosynthesis have shown promising results.

A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms.

High-intensity interval training (HIT) induces skeletal muscle metabolic and performance adaptations that resemble traditional endurance training despite a low total exercise volume. Most HIT studies have employed 'all out', variable-load exercise interventions (e.g. repeated Wingate tests) that may not be safe, practical and/or well tolerated by certain individuals. Our purpose was to determine the performance, metabolic and molecular adaptations to a more practical model of low-volume HIT. Seven men (21 + or - 0.4 years, V(O2peak) = 46 + or - 2 ml kg(-1) min(-1)) performed six training sessions over 2 weeks. Each session consisted of 8-12 x 60 s intervals at approximately 100% of peak power output elicited during a ramp V(O2) peak test (355 + or - 10 W) separated by 75 s of recovery. Training increased exercise capacity, as assessed by significant improvements on both 50 kJ and 750 kJ cycling time trials (P < 0.05 for both). Skeletal muscle (vastus lateralis) biopsy samples obtained before and after training revealed increased maximal activity of citrate synthase (CS) and cytochrome c oxidase (COX) as well as total protein content of CS, COX subunits II and IV, and the mitochondrial transcription factor A (Tfam) (P < 0.05 for all). Nuclear abundance of peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1alpha) was approximately 25% higher after training (P < 0.05), but total PGC-1alpha protein content remained unchanged. Total SIRT1 content, a proposed activator of PGC-1alpha and mitochondrial biogenesis, was increased by approximately 56% following training (P < 0.05). Training also increased resting muscle glycogen and total GLUT4 protein content (both P < 0.05). This study demonstrates that a practical model of low volume HIT is a potent stimulus for increasing skeletal muscle mitochondrial capacity and improving exercise performance. The results also suggest that increases in SIRT1, nuclear PGC-1alpha, and Tfam may be involved in coordinating mitochondrial adaptations in response to HIT in human skeletal muscle.

Surgical Repair of Bilateral Combined Rectus Abdominis and Adductor Longus Avulsion: A Case Report.

CASE: In this case report, we present an adult man who sustained bilateral rectus abdominis and adductor longus avulsions with associated symphyseal instability while playing hockey. The injury was managed surgically, and the patient returned to preinjury level of function. CONCLUSION: To our knowledge, this is the first reported case of such a bilateral injury. The surgical management and outcome add to the current literature, which lacks adequate evidence on the most effective management for injuries of this type.

Fatal Cerebral Fat Embolism After Pelvic and Multiple Long Bone Fractures without Associated Lung Injury: A Case Report.

CASE: A 29-year-old motor vehicle collision passenger presented with fractures of the pelvic ring, bilateral femurs, and right tibia/fibula. All fractures were stabilized with external fixation and fixed definitively 48 hours later. Postoperatively, the patient suffered rapid clinical decline. Emergent head computed tomography (CT) demonstrated tonsillar herniation with loss of gray-white matter differentiation. Although respiratory status remained uncompromised throughout presentation, pathology revealed extensive cerebral fat embolism. CONCLUSION: Fat embolism can traverse the lungs without eliciting an inflammatory response, radiographic infiltrate, or impairing gas exchange. This may lead to a clinically silent, fatal cerebral fat embolism in an intubated, sedated patient.

Does use of a quadrilateral surface plate improve outcome in elderly acetabular fractures?

BACKGROUND: Acetabular fractures in the elderly frequently involve segmental quadrilateral plate injury, yet no consensus exists on how to best control the femoral head medial displacement. Quadrilateral surface plates (QSP) were developed to help buttress these challenging fractures. The study aims to 1) Determine the prevalence of segmental quadrilateral plate fractures (SQPF) in elderly patients; and 2) Assess if utilization of a QSP is associated with improved acetabulum fracture reduction and outcome. METHODS: This was a retrospective study conducted at a level-1 trauma centre. . All patients over 60-years that sustained an acetabular fracture between 2007 and 2019 were reviewed. Pre-operative pelvic radiographs and CT imaging were reviewed for 96 patients, to assess for SQPF. From the 96 patients reviewed, over one third of patients (n = 40, 41.6%) sustained a SQPF. Patients that had an acute-THA (n = 7) were excluded as were patients that underwent an ORIF but did not have a QSP or an anterior column buttress plate (n = 3). The remaining 30 formed the study's cohort. We assessed the ability to achieve and maintain reduction in this elderly population, and compared outcomes using traditional anterior column buttress plates (ilioingual or intra-pelvic approach) versus an intra-pelvic pre-contoured buttress suprapectineal plate (QSP). Outcome measures included: fracture reduction using the Matta classification (desirable: anatomical/imperfect and poor), re-operations, conversion to THA and Oxford Hip Score (OHS) (for the preserved hips). RESULTS: Ten patients had an ORIF with utilization of a QSP (QSP-group), and 20 had an ORIF but did not have the QSP (non-QSP-group). There was no difference in patient demographics between groups. Fracture patterns were also similar (p = 0.6). Postoperative fracture reduction was desirable (anatomical/imperfect) in 17 patients and poor in 13. Improved ability to achieve a desirable reduction was seen in the QSP-group (p = 0.02). Conversion to THA was significantly lower in patients that had a desirable fracture reduction (appropriate: 3/17; poor: 7/13). No patients in the QSP-group have required a THA to-date, compared to 10/20 patients in the non-QSP-group (p = 0.01). The mean time to THA was 1.6 ± 2.1 year. There was no difference in OHS between the two groups (34.4 ± 10.3). CONCLUSION: Elderly acetabulum fractures have a high incidence (approaching 40%) of segmental QPF. Desirable (anatomical/imperfect) fracture reduction was associated with improved outcome. The use of a QSP was associated with improved ability to achieve an appropriate reduction. A QSP should be considered as they are both reliable and reproducible with a significantly improved fracture reduction and lower conversion to THA.

Periacetabular osteotomy with or without arthroscopic management in patients with hip dysplasia: study protocol for a multicenter randomized controlled trial.

BACKGROUND: Hip dysplasia is one of the most common causes of hip arthritis. Its incidence is estimated to be between 3.6 and 12.8% (Canadian Institute for Health Information, Hip and knee replacements in Canada, 2017-2018: Canadian joint replacement registry annual report, 2019; Jacobsen and Sonne-Holm, Rheumatology 44:211-8, 2004). The Periacetabular Osteotomy (PAO) has been used successfully for over 30 years (Gosvig et al., J Bone Joint Surg Am 92:1162-9, 2010), but some patients continue to exhibit symptoms post-surgery (Wyles et al., Clin Orthop Relat Res 475:336-50, 2017). A hip arthroscopy, performed using a small camera, allows surgeons to address torn cartilage inside the hip joint. Although both procedures are considered standard of care treatment options, it is unknown whether the addition of hip arthroscopy improves patient outcomes compared to a PAO alone. To delay or prevent future joint replacement surgeries, joint preservation surgery is recommended for eligible patients. While previous studies found an added cost to perform hip arthroscopies, the cost-effectiveness to Canadian Health care system is not known. METHODS: Patients randomized to the experimental group will undergo central compartment hip arthroscopy prior to completion of the PAO. Patients randomized to the control group will undergo isolated PAO. Patient-reported quality of life will be the primary outcome used for comparison between the two treatment groups as measured by The International Hip Outcome Tool (iHOT-33) (Saberi Hosnijeh et al., Arthritis Rheum 69:86-93, 2017). Secondary outcomes will include the four-square step test and sit-to-stand (validated in patients with pre-arthritic hip pain) and hip-specific symptoms and impairment using the HOOS; global health assessment will be compared using the PROMIS Global 10 Score; health status will be assessed using the EQ-5D-5L and EQ VAS questionnaires (Ganz et al., Clin Orthop Relat Res 466:264-72, 2008) pre- and post-operatively. In addition, operative time, hospital length of stay, adverse events, and health services utilization will be collected. A sub-group of patients (26 in each group) will receive a T1rho MRI before and after surgery to study changes in cartilage quality over time. A cost-utility analysis will be performed to compare costs and quality-adjusted life years (QALYs) associated with the intervention. DISCUSSION: We hypothesize that (1) concomitant hip arthroscopy at the time of PAO to address central compartment pathology will result in clinically important improvements in patient-reported outcome measures (PROMs) versus PAO alone, that (2) additional costs associated with hip arthroscopy will be offset by greater clinical improvements in this group, and that (3) combined hip arthroscopy and PAO will prove to be a cost-effective procedure. TRIAL REGISTRATION: ClinicalTrials.gov NCT03481010 . Registered on 6 March 2020. Protocol version: version 3.

Periacetabular Osteotomy as a Salvage Procedure: Early Outcomes in Patients Treated for Iatrogenic Hip Instability.

BACKGROUND: A periacetabular osteotomy (PAO) can reduce pain and improve quality of life in patients with hip dysplasia. While its utility for patients without traditional radiographic parameters for hip dysplasia has not been previously established, the PAO may help treat patients with hip instability that does not improve following single or multiple hip arthroscopic procedures, or when such procedures lead to hip instability. METHODS: A single-surgeon registry of patients at a single institution was queried to identify patients with a lateral center-edge angle (LCEA) of ≥24° and a Tönnis angle of <10° who underwent PAO because of hip pain and/or instability that failed treatment with hip arthroscopy. Descriptive summary statistics were reported on patient demographics, mean change in LCEA, and patient-reported outcome measures, including the modified Harris hip score (mHHS) and the International Hip Outcome Tool-33 (iHOT-33), at a minimum of 6 months of follow-up. RESULTS: Among 25 patients (mean age, 27.3 ± 6.9 years; 100% women), the mean LCEA increased from 27.2° (range, 24° to 37°) preoperatively to 39.0° ± 5.1° postoperatively (net increase, 11.8° ± 4.5°). Overall, the mean improvement in the mHHS was 11.5 ± 16.9 (preoperative, 59.4 ± 11.6; postoperative, 70.9 ± 20.6) and the mean improvement in the iHOT-33 was 23.8 ± 23.6 (preoperative, 32.2 ± 17.2; postoperative, 56.0 ± 30.0). Eighteen patients (72%) achieved a minimal clinically important improvement in mHHS (mean improvement, 17.4 ± 12.9) and iHOT-33 (mean improvement, 32.4 ± 19.1) scores. In comparison with 7 patients who did not show improvement, the 18 patients who showed improvement had significantly greater mean baseline patient-reported outcome scores. CONCLUSIONS: To our knowledge, these findings provide the first report on outcomes of PAO in patients with hip pain following arthroscopy who do not meet the traditional criteria for acetabular dysplasia. Early benefits in clinical outcomes suggest a novel surgical indication for PAO as a potential salvage option for selected patients; however, longer-term studies are needed. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Arthroscopic acetabular labral debridement in patients forty-five years of age or older has minimal benefit for pain and function.

BACKGROUND: Hip arthroscopy is being performed with expanding indications, commonly including symptomatic labral tears. The effects of various patient factors, including patient age, on clinical outcomes are not well understood. The purpose of the present study was to quantify the postoperative functional and quality-of-life outcomes after arthroscopic debridement of symptomatic labral tears in patients forty-five years of age or older. METHODS: Forty-one patients who were at least forty-five years of age (mean age, 52.7 years [range, 45.5 to 67.0 years]; mean body mass index, 26.1 kg/m² [range, 18.4 to 33.2 kg/m²]; 75.6% female) and who underwent labral debridement at the time of hip arthroscopy were included. Disease-specific clinical outcome measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] and modified Harris hip score [mHHS]) and general health-related measures (12-Item Short Form Health Survey [SF-12]) were collected preoperatively and postoperatively. RESULTS: The reoperation rate was 17% (seven of forty-one) at a mean of 21.3 months, and six of the seven reoperations involved conversion to hip arthroplasty or resurfacing. The overall hip arthroscopy cohort had postoperative improvements in the mean WOMAC pain score (from 54.0 [range, 20 to 90] to 69.4 [range, 0 to 100], p < 0.001), WOMAC function score (from 60.4 [range, 16.2 to 95.6] to 69.1 [range, 10.3 to 100], p = 0.004), SF-12 physical component summary score (from 33.2 to 39.3, p < 0.001), and mHHS (from 56.6 [range, 9.9 to 84.6] to 63.9 [range, 29.7 to 100], p = 0.022). The changes in the WOMAC stiffness score (from 54.6 ± 20.8 to 60.1 ± 28.1, p = 0.157) and SF-12 mental component summary score (from 51.3 ± 11.4 to 51.6 ± 12.2, p = 0.870) were not significant. Thirteen patients (32%) had a good or excellent outcome as indicated by the postoperative mHHS. CONCLUSIONS: Arthroscopic labral debridement in patients forty-five years of age or older was associated with a relatively high reoperation rate and minimal overall improvement in joint-specific and quality-of-life outcome measures. Although differences in some outcome measures were statistically significant, most did not reach the level of the minimum clinically important difference. Arthroscopic debridement of labral tears in this patient population must be approached with caution as the overall clinical benefit was small.

Negative-pressure wound therapy after fasciotomy reduces muscle-fiber regeneration in a pig model.

BACKGROUND: Negative-pressure wound therapy (NPWT) can improve fasciotomy wound closure, but its effects on skeletal muscle are largely unknown. The purpose of this study was to evaluate NPWT effects on skeletal muscle after fasciotomy for compartment syndrome in an animal model and to assess regional variability in muscle fiber regeneration. METHODS: Compartment syndrome was induced in the hindlimb of twenty-two adult female pigs with use of a continuous intracompartmental serum-infusion model. Fasciotomy was performed after six hours, and animals were randomized to receive either wet-to-dry gauze dressings (control group) or NPWT dressings (-125 mm Hg, continuous suction) for seven days. Delayed primary wound closure was attempted at seven days, and the peroneus tertius was harvested for analysis seven days or twenty-one days after fasciotomy. Muscles were weighed, and hematoxylin and eosin-stained samples from four regions of the muscle (superficial central, deep central, lateral, and proximal) were mapped for different cellular morphologies. RESULTS: Muscle weight was greater in the affected limb at all time points with no difference between treatment groups. At seven days, only the deep central samples in the NPWT group had a significantly greater cross-sectional area containing normal fibers as compared with that found in the controls. By twenty-one days, the deep central, lateral, and proximal regions of the NPWT-treated muscles had a smaller cross-sectional area containing normal fiber morphology and a greater cross-sectional area containing only mononucleated cells as compared with the controls. CONCLUSIONS: NPWT did not decrease muscle weight. At twenty-one days, the extent of muscle fiber regeneration after fasciotomy for compartment syndrome was reduced in muscles treated with NPWT for seven days compared with the values in the control group treated with wet-to-dry gauze dressings. CLINICAL RELEVANCE: NPWT may be harmful to skeletal muscle after compartment syndrome requiring fasciotomy and local wound care.

Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance.

Brief, intense exercise training may induce metabolic and performance adaptations comparable to traditional endurance training. However, no study has directly compared these diverse training strategies in a standardized manner. We therefore examined changes in exercise capacity and molecular and cellular adaptations in skeletal muscle after low volume sprint-interval training (SIT) and high volume endurance training (ET). Sixteen active men (21 +/- 1 years, ) were assigned to a SIT or ET group (n = 8 each) and performed six training sessions over 14 days. Each session consisted of either four to six repeats of 30 s 'all out' cycling at approximately 250% with 4 min recovery (SIT) or 90-120 min continuous cycling at approximately 65% (ET). Training time commitment over 2 weeks was approximately 2.5 h for SIT and approximately 10.5 h for ET, and total training volume was approximately 90% lower for SIT versus ET ( approximately 630 versus approximately 6500 kJ). Training decreased the time required to complete 50 and 750 kJ cycling time trials, with no difference between groups (main effects, P