Arthroscopic Repair of Acetabular Cartilage Lesions by Chitosan-Based Scaffold: Clinical Evaluation at Minimum 2 Years Follow-up

Treatment of Hip Cartilage Defects in Athletes

Chondral defects in the athlete's hip are a relatively common occurrence, often presenting with debilitating pain and activity limitation. Preoperative identification of cartilage defects is challenging and there are many different modalities for treatment. Nonsurgical interventions, including activity modification, physical therapy, and injections, play a vital role, especially in less severe cases and as adjuncts to surgical intervention. Treating surgeons must be familiar with the cartilage restoration procedures available, including debridement, microfracture, and various implantation and transplantation options. Safe and effective management of cartilage defects is imperative to an athlete's return to sport. It is also imperative that surgeons are aware of all these various treatment options to determine what modality is best for their patients. This review serves to outline these options, cover the published literature, and provide general guidelines for surgeons when they encounter chondral defects in the office and the operating room.

Beyond the patella: Treatment of cam femoroacetabular impingement syndrome improves anterior knee pain

OBJECTIVES

This study aimed to investigate if there is a relationship between cam femoroacetabular impingement syndrome (cam-FAIS) and chronic anterior knee pain (AKP).

METHODS

This is a pilot retrospective review of 12 AKP patients with no structural anomalies in the patellofemoral joint and no skeletal malalignment in the lower limbs. All the patients were resistant to proper conservative treatment for AKP (AKP-R). Subsequently, these patients developed pain in the ipsilateral hip several months later, and upon evaluation, were diagnosed with cam-FAIS. Arthroscopic femoral osteoplasty and labral repair were performed and clinical follow-up of hip and knee pain and function (Kujala Score and Non-arthritic Hip Score -NAHS-) was carried out.

RESULTS

All the patients showed improvement in the knee and hip pain scores with a statistically significant clinical difference in all of them at 69 months follow up (range: 18 to 115) except one patient without improvement in the groin VAS score post-operatively. Visual analogical scale (VAS) of knee pain improved from 6.3 (range: 5 to 8) to a postoperative 0.5 (range: 0 to 3.5), (p ​< ​0.001). The VAS of groin pain improved from 4.4 (range: 2 to 8) to a postoperative 0.9 (range: 0 to 3), (p ​< ​0.001). NAHS improved from a preoperative 67.9 (range: 28.7 to 100) to a postoperative 88 (range: 70 to 100), (p ​< ​0.015) and knee Kujala's score improved from a preoperative 48.7 (range: 22 to 71) to a postoperative 96 (range: 91 to 100), (p ​< ​0.001).

CONCLUSION

This study's principal finding suggests an association between cam-FAIS and AKP-R in young patients who exhibit normal knee imaging and lower limbs skeletal alignment. Addressing cam-FAIS in these cases leads to resolution of both groin and knee pain, resulting in improved functional outcomes for both joints.

STUDY DESIGN

Retrospective cohort series with a single contemporaneous long-term follow-up.

LEVEL OF EVIDENCE

IV.

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

PURPOSE

To systematically review outcomes of joint preservation procedures for chondral lesions of the hip through analysis of survival rates and patient-reported outcomes (PROs).

METHODS

A literature search from 2018 to May 2023 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in 3 databases: PubMed, Embase, and Google Scholar. Studies were included if they reported on outcomes of patients undergoing hip arthroscopy for the treatment of chondral lesions of the hip joint and if there were quantifiable postoperative outcome measures. Quality assessment was completed using the Methodological Index for Non-Randomized Studies criteria.

RESULTS

Twenty-seven studies were included, with 20 noncomparative and 7 comparative studies. Microfracture (MFx) was the most common procedure, reported in 17 studies. Other procedures include autologous chondrocyte transplantation (ACT) (5 studies), autologous matrix-induced chondrogenesis (AMIC) (3 studies), and MFx in conjunction with CarGel (3 studies). Seven other novel procedures were reported in individual separate studies. Survival rates, defined by no revision surgery or conversion to total hip arthroscopy (THA) at latest follow-up, for MFx (14 studies), AMIC (3 studies), and MFx in conjunction with CarGel (3 studies) ranged from 59.1% to 100%, 92.9% to 100%, and 94.4% to 95.7%, respectively. Survival rates of ACT, biological reconstruction, debridement and abrasion, microfragmented autologous adipose tissue transplantation, and ChondroFiller gel were all reported once in separate studies with rates of 100%, 100%, 85.4%, 100%, and 92.3%, respectively. All studies included PROs, most reporting statistically significant improvements (P < .05) at the latest follow-up.

CONCLUSIONS

Isolated MFx remained the most commonly performed technique, but with lower survival and higher conversion to THA rates than in studies before 2018. Novel techniques that were performed in conjunction with MFx or that avoided MFx altogether had higher overall survival rates despite being minimally performed. Most patients across all techniques demonstrated significant improvements in PROs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Editorial Commentary: Osteochodral Autograft and Allograft Show Favorable Outcomes for High-Grade Hip Femoral Cartilage Lesions, but Caution Is Required for Impaction Injuries and Osteonecrosis

Articular cartilage defects of the hip pose therapeutic challenges. Among patients undergoing hip arthroscopy for femoroacetabular impingement syndrome, more than 20% may have partial- or full-thickness chondral damage, and patients with high-grade (International Cartilage Repair Society grade 3 or 4) damage who undergo arthroscopic treatment of femoroacetabular impingement syndrome have higher rates of reoperation at 10-year follow-up. Arthroscopic and open techniques have been developed to translate cartilage restoration options initially developed in the knee for use in the hip. Arthroscopic options include chondroplasty, microfracture, biologic cartilage scaffolds, autologous chondrocyte implantation, and minced cartilage autograft (albeit more commonly in the acetabulum than the femoral head). Open techniques include autologous chondrocyte grafting, osteochondral autograft transfer (including mosaicplasty), osteochondral allograft transplantation, and arthroplasty. Open osteochondral allograft and autograft transplantation show improved patient-reported outcomes and forestall arthroplasty in young patients with high-grade cartilage defects of the femoral head. A recent review shows survivorship of 70% to 87.5% for allograft and 61.5% to 96% for autograft. At the same time, outcomes are not universally positive, particularly for patients with posttraumatic impaction injuries and high-grade osteonecrosis. Until further data better clarify the indications and contraindications, widespread adoption of open cartilage transplantation to the femoral head should be approached with caution, especially for older patients, in whom the gold standard of total hip arthroplasty has excellent survivorship at long-term follow-up.

Outcomes of arthroscopy of the hip for femoroacetabular impingement based on intraoperative assessment using the Outerbridge classification

Aims

Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system.

Methods

A systematic search was performed on four databases. Studies which involved HA as the primary management of FAI and reported on chondral lesions as classified according to the Outerbridge classification were included. The study was registered on PROSPERO. Demographic data, patient-reported outcome measures (PROMs), complications, and rates of conversion to total hip arthroplasty (THA) were collected.

Results

A total of 24 studies were included with a total of 3,198 patients (3,233 hips). Patients had significantly less improvement in PROMs if they had Outerbridge grade III and IV lesions (p = 0.012). Compared with microfracture, autologous matrix-induced chondrogenesis (AMIC) resulted in significantly reduced rates of conversion to THA (p = 0.042) and of revision arthroscopy (p = 0.038). Chondral repair procedures in these patients also did not significantly reduce the rates of conversion to THA (p = 0.931), or of revision arthroscopy (p = 0.218). However, compared with microfracture, AMIC significantly reduced the rates of conversion to THA (p = 0.001) and of revision arthroscopy (p = 0.011) in these patients. Those with Outerbridge grade III and IV lesions also had significantly increased rates of conversion to THA (p = 0.029) and of revision arthroscopy (p = 0.023) if they had associated lesions of the acetabulum and femoral head. Those who underwent labral debridement had a significantly increased rate of conversion to THA compared with those who underwent labral repair (p = 0.015).

Conclusion

There is universal improvement in PROMs following HA in patients with FAI and associated chondral lesions. However, those with Outerbridge grade III and IV lesions had significantly less improvement in PROMs and a significantly increased rate of conversion to THA than those with Outerbridge grade I and II. This suggests that the outcome of HA in patients with FAI and severe articular cartilage damage may not be favourable.

Recent Developments and Current Applications of Organic Nanomaterials in Cartilage Repair

Regeneration of cartilage is difficult due to the unique microstructure, unique multizone organization, and avascular nature of cartilage tissue. The development of nanomaterials and nanofabrication technologies holds great promise for the repair and regeneration of injured or degenerated cartilage tissue. Nanomaterials have structural components smaller than 100 nm in at least one dimension and exhibit unique properties due to their nanoscale structure and high specific surface area. The unique properties of nanomaterials include, but are not limited to, increased chemical reactivity, mechanical strength, degradability, and biocompatibility. As an emerging nanomaterial, organic nanocomposites can mimic natural cartilage in terms of microstructure, physicochemical, mechanical, and biological properties. The integration of organic nanomaterials is expected to develop scaffolds that better mimic the extracellular matrix (ECM) environment of cartilage to enhance scaffold-cell interactions and improve the functionality of engineered tissue constructs. Next-generation hydrogel technology and bioprinting can be used not only for healing cartilage injury areas but also for extensive osteoarthritic degenerative changes within the joint. Although more challenges need to be solved before they can be translated into full-fledged commercial products, nano-organic composites remain very promising candidates for the future development of cartilage tissue engineering.

An evidence-based update on the management of articular cartilage defects in the hip

Objective

Articular cartilage defects in the hip joint pose a significant surgical challenge and remain one of the most important determinants of success following arthroscopic intervention of the hip. The aim of this literature review was to report on the best available evidence on the various treatment options utilised for articular cartilage defects in the hip.

Material and methods

A comprehensive literature search was performed on PubMed from its inception to October 2021 using the following search strategy: ((hip) and (cartilage or chondral) and (repair or regeneration or restoration or implantation or chondroplasty or chondrogenic)). Two reviewers (KHSK, MG) independently reviewed titles and abstracts to identify articles for the final analysis. Articles were included if they were original research studies (randomised control trials, cohort studies, case-control studies, or comparative studies) on treatment of hip cartilage defects in humans reporting on a minimum of 5 patients. A total of 1172 articles were identified from the initial literature search. Following a thorough selection process, 35 articles were included in the final analysis to synthesise the evidence.

Results

Debridement, microfracture, autologous chondocyte implanatation (ACI) and matrix-induced ACI (MACI) are shown to have good short-to medium-term results. Injectable ACI and MACI have been developed to enable these procedures to be performed via arthroscopic surgery to reduce the post-operative morbidity associated with surgery with promising early results. Large cartilage defects which involved the sub-chondral bone may need the use of osteochondral grafts either autograft or allograft. Newer biological solutions have been developed to potentially deliver a single-stage procedure for hip cartilage injuries but longer-term results are still awaited.

Conclusion

Accurate identification of the extent of the injury helps stratify the defect and plan appropriate treatment. Several surgical techniques have shown good short to medium-term outcomes with ACI, AMIC, mosaicplasty and microfracture. Recent advances have enabled the use of injectable MACI and bioscaffolds which show promising results but in the shorter term. However, one needs to be mindful of the techniques which can be used in their surgical setting with the available resources. In order to thoroughly evaluate the benefits of the different surgical techniques for hip cartilage defects, large scale prospective multi-centre studies are necessary. Perhaps inclusion of such procedures in registries may also yield meaningful and pragmatic results.

Nonoperative and Operative Bone and Cartilage Regeneration and Orthopaedic Biologics of the Hip: An Orthoregeneration Network (ON) Foundation Hip Review

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the hip, including osteonecrosis (aseptic necrosis) involving bone marrow, bone, and cartilage, and chondral injuries involving articular cartilage, synovium, and bone marrow. Promising and established treatment modalities for osteonecrosis include nonweightbearing; pharmacological treatments including low molecular-weight heparin, prostacyclin, statins, bisphosphonates, and denosumab, a receptor activator of nuclear factor-kB ligand inhibitor; extracorporeal shock wave therapy; pulsed electromagnetic fields; core decompression surgery; cellular therapies including bone marrow aspirate comprising mesenchymal stromal cells (MSCs aka mesenchymal stem cells) and bone marrow autologous concentrate, with or without expanded or cultured cells, and possible addition of bone morphogenetic protein-2, vascular endothelial growth factor, and basic fibroblast growth factor; and arterial perfusion of MSCs that may be combined with addition of carriers or scaffolds including autologous MSCs cultured with beta-tricalcium phosphate ceramics associated with a free vascularized fibula. Promising and established treatment modalities for chondral lesions include autologous platelet-rich plasma; hyaluronic acid; MSCs (in expanded or nonexpanded form) derived from bone marrow or other sources such as fat, placenta, umbilical cord blood, synovial membrane, and cartilage; microfracture or microfracture augmented with membrane containing MSCs, collagen, HA, or synthetic polymer; mosaicplasty; 1-stage autologous cartilage translation (ACT) or 2-stage ACT using 3-dimensional spheroids; and autologous cartilage grafting; chondral flap repair, or flap fixation with fibrin glue. Hip pain is catastrophic in young patients, and promising therapies offer an alternative to premature arthroplasty. This may address both physical and psychological components of pain; the goal is to avoid or postpone an artificial joint. LEVEL OF EVIDENCE: Level V, expert opinion.

Biological Augments for Acetabular Chondral Defects in Hip Arthroscopy-A Scoping Review of the Current Clinical Evidence

PURPOSE OF REVIEW

A wide array of joint-preserving surgical techniques exists in the management of acetabular chondral defects (ACDs). The purpose of this review is to summarize the clinical outcomes of the recent biologics used to treat ACDs during hip arthroscopy.

RECENT FINDINGS

Increasing evidence is available for different biological solutions used in the hip. Studies have shown promising outcomes with minimal complications when using biologics as augmentation to microfracture (MF), including different scaffolds or stem cells, or to enhance autologous chondrocyte implantation (ACI). However, data so far is scarce, and more trials and longer follow-ups are needed to better delineate the appropriate indications and benefits for each technique. Presently, the level of evidence is low, but in general, biologics appear safe and trend toward beneficial compared to standard surgical techniques. Augmented MF is recommended for small to medium ACDs, and matrix-assisted ACI or three-dimensional ACI is recommended for medium to large defects.

Outcomes following surgical management of femoroacetabular impingement: a systematic review and meta-analysis of different surgical techniques

Outcomes following different types of surgical intervention for femoroacetabular impingement (FAI) are well reported individually but comparative data are deficient. The purpose of this study was to conduct a systematic review (SR) and meta-analysis to analyze the outcomes following surgical management of FAI by hip arthroscopy (HA), anterior mini open approach (AMO), and surgical hip dislocation (SHD). This SR was registered with PROSPERO. An electronic database search of PubMed, Medline, and EMBASE for English and German language articles over the last 20 years was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We specifically analyzed and compared changes in patient-reported outcome measures (PROMs), α-angle, rate of complications, rate of revision, and conversion to total hip arthroplasty (THA). A total of 48 articles were included for final analysis with a total of 4,384 hips in 4,094 patients. All subgroups showed a significant correction in mean α angle postoperatively with a mean change of 28.8° (95% confidence interval (CI) 21 to 36.5; p < 0.01) after AMO, 21.1° (95% CI 15.1 to 27; p < 0.01) after SHD, and 20.5° (95% CI 16.1 to 24.8; p < 0.01) after HA. The AMO group showed a significantly higher increase in PROMs (3.7; 95% CI 3.2 to 4.2; p < 0.01) versus arthroscopy (2.5; 95% CI 2.3 to 2.8; p < 0.01) and SHD (2.4; 95% CI 1.5 to 3.3; p < 0.01). However, the rate of complications following AMO was significantly higher than HA and SHD. All three surgical approaches offered significant improvements in PROMs and radiological correction of cam deformities. All three groups showed similar rates of revision procedures but SHD had the highest rate of conversion to a THA. Revision rates were similar for all three revision procedures.

Ultrafast, tough, and adhesive hydrogel based on hybrid photocrosslinking for articular cartilage repair in water-filled arthroscopy

A hydrogel scaffold for direct tissue-engineering application in water-irrigated, arthroscopic cartilage repair, is badly needed. However, such hydrogels must cure quickly under water, bind strongly and permanently to the surrounding tissue, and maintain sufficient mechanical strength to withstand the hydraulic pressure of arthroscopic irrigation (~10 kilopascal). To address these challenges, we report a versatile hybrid photocrosslinkable (HPC) hydrogel fabricated though a combination of photoinitiated radical polymerization and photoinduced imine cross-linking. The ultrafast gelation, high mechanical strength, and strong adhesion to native tissue enable the direct use of these hydrogels in irrigated arthroscopic treatments. We demonstrate, through in vivo articular cartilage defect repair in the weight-bearing regions of swine models, that the HPC hydrogel can serve as an arthroscopic autologous chondrocyte implantation scaffold for long-term cartilage regeneration, integration, and reconstruction of articular function.

Large Heterogeneity Among Minimal Clinically Important Differences for Hip Arthroscopy Outcomes: A Systematic Review of Reporting Trends and Quantification Methods

PURPOSE

To perform a systematic review of reporting trends and quantification methods for the minimal clinically important difference (MCID) within the hip arthroscopy literature.

METHODS

Cochrane, PubMed, and OVID/MEDLINE databases were queried for hip arthroscopy articles that reported the MCID. Studies were classified as (1) calculating new MCID values for their specific study-population or (2) referencing previously established MCID values. Data pertaining to patient demographics, study characteristics, outcome measures, method of MCID quantification, MCID value, anchor questions, measurement error, and study from which referenced MCID values were obtained were extracted.

RESULTS

A total of 59 articles with 18,830 patients (19,867 hips) was included. A total of 19 unique outcome measures was reported. A total of 33 (n = 55.9%) studies (follow-up range 6-60 months) used previously established MCID values to assess their study population (MCID values established at a follow-up range 6-31 months). The remaining 26 studies (44.1%) performed new MCID calculations. The MCID values were inconsistent and varied widely (Hip Outcome Score-Activities of Daily Living: 5.0-15.4; Hip Outcome Score-Sports Subscale: 6-25; modified Harris hip score: 2.4-20.9). Among the 33 studies that used previously established MCID values, 10 different studies were cited as the reference. Among the remaining 26 studies that calculated a new MCID value, the most common method was 0.5 standard deviation method (n = 21, 80.8%). Only 3 of 26 (11.5%) studies reported a measurement of error in conjunction with their MCID values.

CONCLUSIONS

Inconsistencies in MCID reporting and quantification methods led to a wide range of MCID values for commonly administered outcome measures within the hip arthroscopy literature-even for the same outcome measures. The majority of studies referenced previously established MCID values with variable ranges of follow-up and applied those values to assess their specific study population at varying follow-ups.

LEVEL OF EVIDENCE

IV, systematic review.

Promising radiological outcome after repair of acetabular chondral defects by microfracture augmented with chitosan-based scaffold: mid-term T2 mapping evaluation

PURPOSE

Radiological evaluation of the repair tissue produced after arthroscopic treatment of acetabular chondral lesions associated with femoroacetabular impingement (FAI) by the chitosan-based scaffold.

METHODS

Patients of age 18-55 years with clinical and radiological features of FAI and non-arthritic non-dysplastic hips were selected for arthroscopic treatment. Full-thickness acetabular chondral defects were filled with chitosan-based scaffold material after microfracture. T2 mapping was carried out for all patients after 24 months using a 1.5-T machine. Nine regions of interest (ROIs) were localized from three consecutive sagittal slices including the area of repair. T2 relaxation times of ROIs in the repair area were compared with the corresponding posterior cartilage.

RESULTS

Twenty-one patients, 17 men and 4 women, underwent arthroscopic treatment of full-thickness acetabular chondral defects with mean size of 3.6 ± 1 cm² (range 2-6 cm²). Zone 2 was affected in all cases while zone 3 was involved in 13 cases. T2 relaxation values were collected from 189 ROIs for quantitative analysis. Within the peripheral repair area, the mean T2 value was 49.1 ± 7.2 ms (ms), while ROIs of the central repair area had mean T2 values of 50.2 ± 7.1 ms. Posterior cartilage showed mean T2 value of 46.2 ± 7.6 ms CONCLUSION: Arthroscopic microfracture of large full-thickness acetabular chondral defects with chitosan-based scaffold produced a homogenous repair tissue similar to the corresponding native cartilage of the same joint on quantitative T2 mapping at mid-term follow-up.

CLINICAL RELEVANCE

augmentation of the microfracture by chitosan-based scaffold is a promising modality for treatment of large full-thickness acetabular defects.

LEVEL OF EVIDENCE

IV.

Leveraging advances in chemistry to design biodegradable polymeric implants using chitosan and other biomaterials

The metamorphosis of biodegradable polymers in biomedical applications is an auspicious myriad of indagation. The utmost challenge in clinical conditions includes trauma, organs failure, soft and hard tissues, infection, cancer and inflammation, congenital disorders which are still not medicated efficiently. To overcome this bone of contention, proliferation in the concatenation of biodegradable materials for clinical applications has emerged as a silver bullet owing to eco-friendly, nontoxicity, exorbitant mechanical properties, cost efficiency, and degradability. Several bioimplants are designed and fabricated in a way to reabsorb or degrade inside the body after performing the specific function rather than eliminating the bioimplants. The objective of this comprehensive is to unfurl the anecdote of emerging biological polymers derived implants including silk, lignin, soy, collagen, gelatin, chitosan, alginate, starch, etc. by explicating the selection, fabrication, properties, and applications. Into the bargain, emphasis on the significant characteristics of current discernment and purview of nanotechnology integrated biopolymeric implants has also been expounded. This robust contrivance shed light on recent inclinations and evolution in tissue regeneration and targeting organs followed by precedency and fly in the ointment concerning biodegradable implants evolved by employing fringe benefits provided by 3D printing technology for building tissues or organs construct for implantation.

Reporting Clinical Significance in Hip Arthroscopy: Where Are We Now?

BACKGROUND

Although p values are standard for reporting statistical significance of patient-reported outcome measures (PROMs), the shift toward clinically important outcome values, including minimal clinically important difference (MCID) and substantial clinical benefit (SCB), necessitates re-evaluation of the current literature.

QUESTIONS/PURPOSES

We sought to answer two questions regarding studies on primary hip arthroscopy performed for the treatment of femoroacetabular impingement syndrome (FAIS). (1) Do such studies reporting statistical significance on common PROMs meet published MCID/SCB thresholds? (2) What proportion of such studies report both statistical and clinical significance?

METHODS

We identified four papers published in two journals defining MCID/SCB values on the modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sport (HOS-Sport), international Hip Outcome Tool (iHOT-33), and its short version (iHOT-12) for different groups of FAIS patients undergoing hip arthroscopy. We reviewed these two journals from the dates of publication to the present to identify papers reporting changes in post-operative PROMs. The difference in pre- and post-operative scores on each PROM was calculated and compared to MCID/SCB thresholds.

RESULTS

Twelve studies were included. Ten studies (83%) evaluated mHHS (90% met MCID, 50% met SCB), seven (58%) evaluated HOS-ADL (100% met MCID/SCB) and HOS-Sport (100% met MCID, 57% met SCB), and one (8%) evaluated iHOT-33 (met MCID/SCB) and iHOT-12 (met MCID). Most studies met MCID and SCB at both 1- and 2-year timepoints. Of the studies evaluated, 50% reported clinical relevance.

CONCLUSIONS

Nearly all studies evaluated met MCID, while fewer met SCB. Only half discussed these clinical measures. It is proposed that all future studies report both statistical and clinical significance as standard best practice.

Acetabular cartilage repair: state of the art in surgical treatment

Hip preservation has emerged as a developing surgical subspecialty with a variety of tools to address hip joint pain and dysfunction. Cartilage tears and delamination are caused by injury to the hip and can ultimately progress to osteoarthritis. It has been established that the acetabulum is particularly at risk of cartilage injury secondary to trauma, hip dysplasia and hip impingement. In spite of the high frequency of acetabular cartilage lesions based on our experience and the literature, there is no consensus as to the optimal treatment of these lesions. This review article highlights the challenges in treating cartilage injuries of the acetabulum with a particular emphasis on published studies and technical considerations in performing these procedures.

Teamwork in hip preservation: the ISHA 2019 Annual Scientific Meeting

Hip preservation surgery is now an established part of orthopedic surgery and sports medicine. This report describes the key findings of the 11th Annual Scientific Meeting of International Society for Hip Arthroscopy-the International Hip Preservation Society-in Madrid, Spain from 16 to 19 October 2019. Lectures, seminars and debates explored the most up-to-date and expert views on a wide variety of subjects, including: diagnostic problems in groin pain, buttock pain and low back pain; surgical techniques in acetabular dysplasia, hip instability, femoroacetabular impingement syndrome, labral repair and reconstruction, cartilage defects, adolescent hips and gluteus medius and hamstring tears; and new ideas about femoral torsion, hip-spine syndrome, hip capsule surgery, impact of particular sports on hip injuries, registries, robotics and training for hip preservation specialists. Surgeons, sports physicians, radiologists and physiotherapists looking after young people with hip problems have an increasingly sophisticated armoury of ideas and techniques with which to help their patients. The concept of hip preservation has developed incredibly fast over the last decade; now it is clear that the best results can only be achieved by a multidisciplinary team working together. The 2020s will be the decade of 'Teamwork in Hip Preservation'.

Current hip cartilage regeneration/repair modalities: a scoping review of biologics and surgery

PURPOSE

The rapidly growing and emerging nature of biologics have made indications for regenerative and reparative hip therapies ever changing, with at times only early-stage evidence for their use. The purpose of this study was to review and summarize the currently available data on the management of hip cartilage injuries and osteoarthritis.

METHODS

A scoping review of the available scientific literature for hip biologics was performed, with available evidence for hyaluronic acid (HA), platelet rich plasma (PRP), stem/stromal cells, microfracture, mosaicplasty, osteochondral allograft, and cell-based therapies investigated.

RESULTS

To date, there exist better guidelines and further consensus concerning knee joint biologic treatments than the hip due to a greater number of studies as well as the more recent emergence of hip preservation approaches. However, increasing evidence is available for the selective implementation of biologics on an individualized basis with attention to lesion size and location.

CONCLUSION

Orthopedic surgeons are at an exciting crossroads in medicine, where hip biologic therapies are evolving and increasingly available. Timetested interventions such as arthroplasty have shown good results and still have a major role to play but newer, regenerative approaches have the potential to effectively delay or reduce the requirement for such invasive procedures.

Approach to a Failed Hip Arthroscopy

PURPOSE OF REVIEW

Hip arthroscopy has seen increasing utilization over the last decade. This is largely related to increased recognition and improved techniques for treating femoroacetabilar impingement (FAI). Though hip arthroscopy generally yields favorable outcomes, there are a subset of patients who have residual or recurrent symptoms that require reoperation. The current review discusses an algorithmic approach to evaluating patients following a failed hip arthroscopy including a framework for clinical and radiographic assessment, available treatment options, and associated outcomes in revision surgery.

RECENT FINDINGS

Residual FAI has been demonstrated to be the most common indication for revision arthroscopy. Other indications include residual or recurrent labral pathology, gross instability, microinstability, or adhesions. Appropriate history and imaging are important to determine the cause for residual symptoms. Novel techniques including labral and capsular reconstruction, and modified remplissage procedures have been developed to deal with complex revision cases. Though studies have shown improved outcomes after revision surgery, they have been shown to result in inferior outcomes compared to a matched cohort following primary hip arthroscopy. Management of a failed hip arthroscopy remains a complex problem. Focused history, cross-sectional imaging, and revision hip arthroscopy with novel techniques can improve outcomes, albeit to a lesser extent than patients undergoing successful primary hip arthroscopy. The information provided here can help guide treatment and set appropriate patient expectations for revision surgery.

Single-Stage Arthroscopic Autologous Matrix-Enhanced Chondral Transplantation (AMECT) in the Hip

Chondral defects of the acetabulum in patients with femoroacetabular impingement syndrome are an increasingly recognized cause of worse outcomes after treatment. Multiple procedures have been described for the treatment of hip cartilage lesions including microfracture, autologous chondrocyte implantation, matrix-induced autologous chondrocyte implantation, and autograft and allograft transplantation. However, many of these techniques have poor long-term outcomes, require multiple surgical procedures, or rely on planned preoperative identification of the chondral lesion. This Technical Note describes our technique of autologous matrix-enhanced chondral transplantation, a single-stage treatment for acetabular cartilage lesions that harvests chondral tissue from the femoral cam deformity and combines it with chondral extracellular matrix, growth factors, and autologous peripheral blood.

Physical Activity Following Hip Arthroscopy in Young and Middle-Aged Adults: A Systematic Review

Background

Hip arthroscopy is a common surgical intervention for young and middle-aged adults with hip-related pain and dysfunction, who have high expectations for returning to physical activity following surgery. The purpose of this review was to evaluate the impact of hip arthroscopy on physical activity post-arthroscopy.

Methods

A systematic search of electronic databases was undertaken in identifying studies from January 1st 1990 to December 5th 2019. The search included English language articles reporting physical activity as an outcome following hip arthroscopy in adults aged 18-50 years. Quality assessment, data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 234) were assessed for eligibility following screening of titles and abstracts (n = 2086), yielding 120 studies for inclusion. The majority (86%) of the studies were level 4 evidence. One study reported objective activity data. The most frequently occurring patient-reported outcome measure was the Hip Outcome Score-sport-specific subscale (HOS-SS, 84% of studies). Post--arthroscopy improvement was indicated by large effect sizes for patient-reported outcome measures (standard paired difference [95% confidence interval] −1.35[−1.61 to −1.09] at more than 2 years post-arthroscopy); however, the majority of outcome scores for the HOS-SS did not meet the defined level for a patient-acceptable symptom state.

Conclusion

The current level of available information regarding physical activity for post arthroscopy patients is limited in scope. Outcomes have focused on patients’ perceived difficulties with sport-related activities with a paucity of information on the type, quality and quantity of activity undertaken.

Level of Evidence

Level IV, systematic review of Level 2 through to Level 4 studies

3D-bioprinting a genetically inspired cartilage scaffold with GDF5-conjugated BMSC-laden hydrogel and polymer for cartilage repair

Rationale: Articular cartilage injury is extremely common in congenital joint dysplasia patients. Genetic studies have identified Growth differentiation factor 5 (GDF5) as a shared gene in joint dysplasia and OA progression across different populations. However, few studies have employed GDF5 in biological regeneration for articular cartilage repair. Methods & Results: In the present study, we report identified genetic association between GDF5 loci and hip joint dysplasia with genome-wide association study (GWAS). GWAS and replication studies in separate populations achieved significant signals for GDF5 loci. GDF5 expression was dysregulated with allelic differences in hip cartilage of DDH and upregulated in the repaired cartilage in a rabbit cartilage defect model. GDF5 in vitro enhanced chondrogenesis and migration of bone marrow stem cells (BMSCs), GDF5 was tested in ectopic cartilage generation with BMSCs by GDF5 in nude mice in vivo. Genetically inspired, we further generated functional knee articular cartilage construct for cartilage repair by 3d-bioprinting a GDF5-conjugated BMSC-laden scaffold. GDF5-conjugated scaffold showed better cartilage repairing effects compared to control. Meanwhile, transplantation of the 3D-bioprinted GDF5-conjugated BMSC-laden scaffold in rabbit knees conferred long-term chondroprotection. Conclusions: In conclusion, we report identified genetic association between GDF5 and DDH with combined GWAS and replications, which further inspired us to generate a ready-to-implant GDF5-conjugated BMSC-laden scaffold with one-step 3d-bioprinting for cartilage repair.

Editorial Commentary: Acetabular Cartilage Repair: A Critically Important Frontier in Hip Preservation

Articular cartilage damage to the acetabulum is frequently associated with femoroacetabular impingement, and there are considerable long-term implications for such injury with regard to maintenance of a healthy hip joint and quality of life. Developing treatments capable of restoring articular cartilage to acetabular cartilage defects is of great importance if hip preservation treatments are to be successful. Ideally, such methods should be performed in a minimally invasive manner and be capable of restoring durable repair tissue that reconstitutes a healthy osteochondral unit and that continues to function effectively over the long term.