Acetabular Chondral Lesions Associated With Femoroacetabular Impingement Treated by Autologous Matrix-Induced Chondrogenesis or Microfracture: A Comparative Study at 8-Year Follow-Up

Trends in Cartilage Repair Techniques for Chondral Defects in the Hip in Germany: An Epidemiological Analysis from 2006 to 2022

Cartilage repair techniques for chondral defects in the hip are crucial for treating conditions like femoroacetabular impingement, developmental dysplasia, and osteonecrosis, especially in young patients to delay the progression of osteoarthritis. This study aims to present age and sex distributions and trends in hip-preserving surgeries in Germany from 2006 to 2022, analyzing 116,179 procedures using the German OPS coding system. The procedures were categorized into three groups: debridement, refixation, and regeneration. Arthroscopy was more common than arthrotomy (98,916 vs. 17,263). Males underwent more procedures than females (63,771 vs. 52,408). Debridement had a monomodal age distribution peaking at 43.42 years, while refixation and regeneration exhibited bimodal patterns. Regenerative procedures were primarily performed on younger patients (average 27.73 years). A Joinpoint analysis showed an initial increase in procedures, peaking around 2013, followed by a decline. Arthroscopic procedures peaked at approximately 9000 in 2013, whereas arthrotomies peaked at around 1200 after 2014. The decline in procedures post-2013 may reflect refined surgical indications and a shift towards outpatient settings. These findings underscore the trend towards minimally invasive, scaffold-based treatments, with regenerative techniques showing promising outcomes in younger patients. Future research should focus on prospective comparative studies and cost-benefit analyses to guide clinical decision-making.

Editorial Commentary: The Ideal Treatment Option for Hip Cartilage Repair Remains Elusive and Requires Consideration of Individual Patient Factors

Arthroscopic treatment of hip chondral lesions is a challenge. Recent research shows arthroscopic debridement with preservation of the subchondral bone plate shows superior results compared with microfracture. The results of microfracture can be unpredictable, largely because of the formation of fibrocartilage, which lacks the durability of hyaline cartilage. Autologous matrix-induced chondrogenesis has emerged as a promising alternative. This technique combines microfracture or abrasion with the application of a collagen membrane and aims to enhance the quality of the repair tissue. Autologous matrix-induced chondrogenesis not only improves patient-reported outcomes but also decreases the rate of conversion to total hip arthroplasty when compared with microfracture. Yet, the results remain only fair and variable. Autologous chondrocyte implantation, which involves the cultivation and reimplantation of chondrocytes, although more labor-intensive, may lead to a more robust and durable repair. In addition, newer methods like minced cartilage implantation show encouraging early results. We are in the early stages of understanding cartilage repair, and individual patient factors, such as size of the lesion, patient age, activity level, and coexisting conditions all require consideration.

Long-term Survivorship and Outcomes of Patients Without Dysplasia Undergoing Capsular Repair During Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome

BACKGROUND

There is a paucity of literature evaluating long-term outcomes and survivorship of patients undergoing primary hip arthroscopy with capsular repair for femoroacetabular impingement syndrome (FAIS).

PURPOSE

To report 10-year survivorship and patient-reported outcomes (PROs) after primary hip arthroscopy with capsular repair for FAIS and evaluate the effect of capsular repair in patients at the highest risk for conversion to arthroplasty.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed on all patients undergoing primary hip arthroscopy with capsular repair between October 2008 and February 2011. Patients with a minimum 10-year follow-up on the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and visual analog scale for pain (VAS) scores were selected. The preoperative and minimum 10-year follow-up Hip Outcome Score-Sports Specific Subscale (HOS-SSS) scores were also reported, if available. Patients with ipsilateral hip surgery, worker's compensation, Tönnis osteoarthritis grade >1, and hip dysplasia (lateral center-edge angle <25°) were excluded. Survivorship, PROS, and clinical benefit-minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS)-were reported. An additional propensity-matched subanalysis was performed on patients at the highest risk for conversion to arthroplasty, comparing patients undergoing capsular repair to patients with unrepaired capsules.

RESULTS

A total of 145 (n = 130 patients) out of 180 eligible hips (n = 165 patients) had a minimum 10-year follow-up (80.6%). Also, 126 hips (86.9%) belonged to women, and 19 hips (13.1%) belonged to men. The mean patient age was 30.3 ± 12.9 years. The survivorship rate was 91% at the 10-year follow-up. The cohort experienced significant improvements (P < .001) in the mHHS, NAHS, HOS-SSS, and VAS for pain scores. Moreover, the cohort achieved high rates of the PASS for the mHHS (89.8%), high rates of the MCID for the mHHS (82.4%), and high rates of the MCID for VAS for pain (80.6%) scores. In the propensity-matched subanalysis performed on patients with the highest risk for arthroplasty, 29 hips with capsular repair were matched to 81 hips with unrepaired capsules. While both groups experienced significant improvements in all PROs (P < .05), the group without capsule repair trended toward a higher conversion to arthroplasty rate when compared with the repair group. In addition, an odds ratio was calculated for the likelihood of converting to arthroplasty after having an unrepaired capsule compared with capsular repair (2.54 [95% CI, 0.873-7.37]; P = .087).

CONCLUSION

Patients undergoing primary hip arthroscopy with capsular repair experienced a high survivorship rate of 91% at a minimum 10-year follow-up. Patients who did not convert to arthroplasty saw favorable improvements in PROs and achieved high clinical benefit rates. In addition, among those patients at the highest risk for conversion to arthroplasty, a trend toward greater survivorship was observed with capsular repair.

Chondral regeneration in femoroacetabular lesions is favoured using peripheral blood stem cells with hyaluronan-based scaffold and micro-drilling: A prospective cohort study

Purpose

To determine whether intra-articular injections of peripheral blood stem cells (PBSC) with hyaluronan (HA)-based scaffold improve articular cartilage regeneration in chondral injuries caused by mixed-femoroacetabular impingement syndrome (FAIS) over a period longer than 24 months post-hip arthroscopy.

Methods

In this prospective cohort study, patients with mixed-FAIS and chondral injury ≥ IIIB according to the International Cartilage Regeneration and Joint Preservation Society grade or III/IV of Konan/Haddad classification underwent intra-articular injection of PBSC with an HA-based scaffold and micro-drillings during hip arthroscopy. The degree of chondral repair was measured at baseline and 5 years using the International Cartilage Repair Society morphologic score system (MSS) as the primary outcome. Pain was measured at baseline and 5 years using the Visual Analogue Scale for Pain (VAS Pain), and hip functionality was measured at baseline (presurgery), 6 months, 1 year, and 5 years using the Hip Outcome Score (HOS). The largest diameter of injury, median follow-up, side effects, complications, and improvements were described. T-test, ANOVA with multiple comparisons, and statistical power were estimated.

Results

From initially 34 cases, 25 patients were enrolled. The median follow-up was 5.1 ± 0.3 years. One patient (4%) reported a few side effects with filgrastim administration. No infection, tumours, or synovitis was reported. The largest diameters in zones two, three, and four were 12.4 ± 3.1 mm (n = 8), 13.5 ± 2.8 mm (n = 14), and 11.4 ± 1.9 mm (n = 3), respectively. Ninety-two percent (23/25) of patients improved their outcomes. The MSS and HOS increased from 3.8 ± 1.1 to 9.6 ± 1.5 pts (p < 0.001) and from 65.5 ± 13.0 to 93.9 ± 2.4 pts (p < 0.001), respectively. The VAS-Pain decreased from 5.3 ± 0.7 to 1.3 ± 0.6 mm (p < 0.001). The obtained a posteriori power-size was 0.99.

Conclusion

The intervention suggests a favourable impact on articular cartilage regeneration and clinical outcomes for hip chondral lesions in mixed-FAIS injuries after a median follow-up of 5.1 ± 0.3 years.

Level of Evidence

Level IV.

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.

Autologous Matrix-Induced Chondrogenesis for the Treatment of Hip Acetabular Chondral Lesions Demonstrates Improved Outcomes: A Systematic Review

PURPOSE

To systematically investigate the outcomes of patients who underwent autologous matrix-induced chondrogenesis (AMIC) during hip arthroscopy for the treatment of acetabular chondral lesions due to femoroacetabular impingement syndrome.

METHODS

PubMed and Cochrane were queried in June 2022 to conduct this systematic review using the following keywords: "femoroacetabular impingement," "arthroscopy," "microfracture," and "autologous matrix-induced chondrogenesis." Articles were included if they reported on patient-reported outcomes of AMIC during hip arthroscopy to treat chondral lesions of the hip. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Each study was queried for demographics, lesion classification, surgical treatment, patient-reported outcome scores, revision arthroscopy, and conversion to total hip arthroplasty (THA). A qualitative subanalysis was performed to compare patients undergoing AMIC to patients undergoing microfracture alone if included studies also assessed results of microfracture alone.

RESULTS

Four studies met inclusion criteria and assessed 209 hips undergoing AMIC. The included studies consisted of 99 male and 110 female patients. Mean postoperative follow-up ranged from 1 to 8 years, and mean patient age ranged from 34.3 to 45 years. Three of the 4 included studies reported the modified Harris Hip Score, and all 3 of these studies reported statistically significant improvement in the modified Harris Hip Score at final follow-up (P < .001) with mean preoperative values ranging from 44.5 to 62.8 and mean postoperative values ranging from 78.8 to 95.8. Two of the 4 studies compared patients treated with AMIC to microfracture alone. In these 2 studies, the AMIC groups reported 0 patients converting to THA while the microfracture-alone groups reported a highly variable rate of conversion to THA (2%-32.6%).

CONCLUSIONS

Patients who underwent hip arthroscopy and AMIC for the treatment of femoroacetabular impingement syndrome and acetabular chondral lesions demonstrated improved patient-reported outcomes and low rates of secondary surgeries at short-term follow-up. STUDY DESIGN: Level IV, systematic review of Level III and IV studies.

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.

Mid-term results of autologous matrix-induced chondrogenesis for large chondral defects in hips with femoroacetabular impingement syndrome

Aims

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI).

Methods

This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm2, who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain.

Results

A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (rs = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs.

Conclusion

Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials.

Microfracture of Acetabular Chondral Lesions Is Not Superior to Other Cartilage Repair Techniques in Patients With Femoroacetabular Impingement Syndrome: A Systematic Review

PURPOSE

To perform a systematic review to compare clinical outcomes of hip arthroscopy patients undergoing microfracture (MFx) versus other cartilage repair procedures for chondral lesions of the acetabulum.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines by searching PubMed, the Cochrane Library, and Embase to identify comparative studies that directly compared outcomes between MFx and other cartilage repair procedures for full-thickness chondral lesions of the acetabulum identified during hip arthroscopy. The search phrase used was: hip AND arthroscopy AND microfracture. Patients were evaluated based on reoperation rates and patient-reported outcomes.

RESULTS

Six studies (all Level III evidence) met inclusion criteria, including a total of 202 patients undergoing microfracture (group A) and 327 patients undergoing another cartilage repair procedure (group B). Mean patient age ranged from 35.0 to 45.0 years. Mean follow-up time ranged from 12.0 to 72.0 months. Significantly better patient-reported outcomes (PROs) were found in patients undergoing treatment with bone marrow aspirate concentrate, microfragmented adipose tissue concentrate, autologous matrix-induced chondrogenesis, and a combination of autologous matrix-induced chondrogenesis and bone marrow aspirate concentrate compared with MFx. No studies found significantly better postoperative PROs in group A. The reoperation rate ranged from 0% to 34.6% in group A and 0% to 15.9% in group B. Three of 5 studies reporting on reoperation rate found a significantly greater reoperation rate in group A, with no difference in the other 2 studies.

CONCLUSIONS

The literature on MFx of acetabular chondral lesions is limited and heterogeneous. Based on the available data, MFx alone results in a greater or equivalent reoperation rate and inferior or equivalent PROs compared with other cartilage repair procedures for acetabular chondral lesions in patients with femoroacetabular impingement syndrome.

LEVEL OF EVIDENCE

Level III, systematic review of level III studies.

Positive outcomes following Autologous Matrix-Induced Chondrogenesis (AMIC) in the treatment of retropatellar chondral lesions: a retrospective analysis of a patient registry

BACKGROUND

The patellofemoral joint is a challenging environment for treating chondral defects. Among the surgical options for the treatment of chondral defects, the single-stage Autologous Matrix-Induced Chondrogenesis (AMIC) procedure uses a porcine collagen I/III membrane to enhance bone-marrow stimulation. However, longer term outcomes data are rare for this specific indication. In order to provide real-world information, an ongoing registry has been established to record patient data and outcomes when AMIC is used to treat chondral and osteochondral lesions.

METHODS

Patient data were retrieved from an ongoing, prospective, multisite registry of patients who had undergone AMIC treatment of chondral defects. We identified 64 patients who had undergone AMIC for patellofemoral chondral defects and for whom pre-operative and at least 1 post-operative score were available were included in this retrospective data analysis. Outcomes were assessed via the KOOS, VAS pain, and the Lysholm scores. Outcomes at the post-operative time-points were analysed using a factorial ANOVA with post-hoc testing while linear regression was used to assess associations between the change in the Lysholm score and lesion size.

RESULTS

There was a significant improvement in Lysholm, VAS pain, and KOOS scores from pre-operative to the 1st year post-operative (p < 0.001), and this was maintained during the follow-up.

CONCLUSIONS

The forces exerted on the patellofemoral joint make this a challenging scenario for chondral repair. Our data demonstrates that the AMIC procedure with a collagen I/III membrane is an effective treatment for retropatellar cartilage lesions, and provides reliable results, with decreased pain and improved function. Importantly, these improvements were maintained through the follow-up period.

Minced Cartilage Implantation in Acetabular Cartilage Defects: Case Series with 2-Year Results

OBJECTIVE

The objective was to evaluate clinical outcome and safety of arthroscopic, autologous minced cartilage implantation for acetabular cartilage lesions observed during hip arthroscopy to treat femoroacetabular impingement syndrome (FAIS).

DESIGN

Eleven male patients, average age: 29.4 ± 5.4 years, average body mass index (BMI): 24.2 ± 2.2 kg/m2, scheduled for hip arthroscopy due to FAIS accompanied by an acetabular cartilage lesion were included in the case series. Cartilage tissue was harvested and minced from the loose cartilage flap at the chondrolabral lesion by arthroscopic shaver, augmented with autologous conditioned plasma, implanted into the defect, and fixated by autologous thrombin. Concomitant interventions were performed as indicated. The patients were evaluated preoperatively and at 24-month follow-up, using the International Hip Outcome Tool-12 (iHOT-12) and Visual Analog Scale (VAS) pain score and by magnetic resonance imaging (MRI) using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) grading scale at the 2-year follow-up.

RESULTS

The defect size was on average 3.5 cm2 (1.5-4.5 cm2). From preoperatively to 2 years postoperatively, the iHOT-12 significantly improved from 50.2 ± 18 to 86.5 ± 19 (P < 0.0001), and pain score decreased from 5.6 ± 1.8 to 1.0 ± 1.5 (P < 0.0001) on the Visual Analog Scale pain score. Regarding functional outcome and pain, 10 of the 11 patients and all patients reached the minimal clinically important difference (MCID), respectively. The postoperative average MOCART score was 87.2 (± 9.2). No adverse events or reoperations were observed.

CONCLUSIONS

Arthroscopic, autologous minced cartilage implantation for treating full-thickness acetabular cartilage lesions in FAIS shows statistically and clinically significant improvement at short-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.

Minimum 10-year Survivorship and Clinical Outcomes Following Primary Hip Arthroscopy with Acetabular Microfracture

PURPOSE

To report minimum 10-year follow-up survivorship, defined as non-conversion to total hip arthroplasty (THA), and patient-reported outcome scores (PROS) after primary hip arthroscopy with acetabular microfracture in the setting of femoroacetabular impingement syndrome (FAIS) and acetabular chondral lesions, respectively.

METHODS

Data were prospectively collected and retrospectively analyzed on all patients who underwent a primary hip arthroscopy and received an acetabular microfracture between June 2009 and January 2011. Patients with a minimum 10-year follow-up for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and the visual analog scale (VAS) for pain were included. If available, the minimum 10-year follow-up for the Hip Outcome Score-Sport-Specific Subscale was reported. The demographics, intraoperative findings, surgical procedures, PROS, rate of achieving the minimal clinical important difference (MCID), and secondary surgeries were analyzed and reported.

RESULTS

Twenty-two hips (20 patients) were included in the study, and the mean follow-up time was 124.5 ± 2.2 months. There were 17 hips (77.3%) from males and 5 hips (22.7%) from females. The average patient age at the time of surgery was 42.3 years ± 9.6. All patients on average experienced statistically significant improvement (P < .05) between preoperative and minimum 10-year follow-up scores for all PROs. In total, 77.3% of the patients did not require conversion to THA. Additionally, 83.3% of the patients achieved the MCID for the mHHS, NAHS, and VAS for pain.

CONCLUSION

At a minimum 10-year follow-up, survivorship of 77.3% was reported for patients who underwent primary hip arthroscopy with acetabular microfracture for the treatment of FAIS and focal/full-thickness acetabular cartilage lesions. Further, in the patients that did not require THA conversion, significant improvement in all PROS was demonstrated.

LEVEL OF EVIDENCE

IV, case-series study.

Patients with Small Acetabular Cartilage Defects Caused by Femoroacetabular Impingement Do Not Benefit from Microfracture

OBJECTIVE

According to current recommendations, large cartilage defects of the hip over 2 cm2 are suggested to undergo autologous chondrocyte transplantation (ACT), while small defects should be treated with microfracture. We investigated if patients with small chondral defects of the hip joint (≤100 mm2) actually benefit from microfracture.

DESIGN

In this retrospective multicenter cohort study 40 patients with focal acetabular cartilage defects smaller than 100 mm2 and of ICRS grade ≥2 caused by femoroacetabular impingement were included. Twenty-six unrandomized patients underwent microfracture besides treatment of the underlying pathology; in 14 patients cartilage lesions were left untreated during arthroscopy. Over a mean follow-up of 28.8 months patient-reported outcome was determined using the iHOT33 (international hip outcome tool) and the VAS (visual analog scale) for pain.

RESULTS

The untreated group showed a statistically significant improvement of the iHOT33 after 12 (p = 0.005), 24 (p = 0.019), and 36 months (p = 0.002) compared to the preoperative score, whereas iHOT33 in the microfracture group did not reveal statistically significant changes over time. There was no significant difference between both groups on any time point. Regarding pain both groups did not show a significant improvement over time in the VAS.

CONCLUSION

The subjective outcome of patients with small cartilage defects of the hip (≤100 mm2) improves 12 months after arthroscopic FAIS surgery without any cartilage treatment. However, no improvement could be seen after microfracture. Therefore, a reserved surgical treatment for small cartilage defects of the hip under preservation of the subchondral bone is recommended especially if a simultaneous impingement correction is performed.

Platelet-Rich Plasma Is Not Associated With Improved Outcomes Following Hip Femoroacetabular Impingement Surgery: Very Low-Quality Evidence Suggests Hyaluronic Acid and Cell-Based Therapies May Be Beneficial—A Systematic Review of Biological Treatments

Purpose

To examine the efficacy of biologic agents in the treatment of cartilage defects associated with femoroacetabular impingement (FAI).

Methods

PubMed, Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews were reviewed by 2 independent reviewers for eligible studies. We included randomized and nonrandomized control trials as well as uncontrolled case series and retrospective studies. Studies were excluded if they included injections of corticosteroids, papers that described technique only, review papers, and those not in the English language. Demographics, treatment type, outcome of treatment, and complications were extracted, whereas risk of bias and study quality were assessed independently using the risk of bias tool (ROB2) and effective public health practice project tool. A narrative synthesis was performed, and standardized mean differences were reported. Certainty of evidence was assessed using the GRADE approach.

Results

Eighteen studies consisting of 1,024 patients met the inclusion criteria. Three studies involved the use of platelet-rich plasma (PRP) as an adjuvant to surgery and were included in the meta-analysis. Three studies administered hyaluronic acid (HA) as a primary treatment. Twelve involved various cell-based methods of chondrocyte stimulation for cartilage defects associated with FAI, but heterogeneity did not allow for pooling. Low-quality evidence indicates PRP is not associated with improved outcomes following surgery (mean difference –1.42, 95% confidence interval –3.95 to 1.11, P = .27). Very-low-quality evidence suggests HA (standardized mean difference 1.15, 95% confidence interval 0.64-1.66, P < .001, Z = 4.39) and cell-based therapies may improve function and pain in patients with FAI.

Conclusions

Low-quality evidence indicates PRP is not associated with improved outcomes following hip FAI surgery, and very-low-quality evidence suggests HA and cell-based therapies may improve outcomes.

Level of Evidence

systematic review of Level I-V studies.

Conservative therapy versus arthroscopic surgery of femoroacetabular impingement syndrome (FAI): a systematic review and meta-analysis

Purpose

FAI (femoroacetabular impingement syndrome) is a common cause of hip pain, resulting in a decreased life quality. This study aims to compare the postoperative clinical outcome between arthroscopic surgery (AT) and conservative treatment (CT).

Method

The six studies were selected from PubMed, Embase and OVID database. The data were extracted and analyzed by RevMan5.3. Mean differences and 95% confidence intervals were calculated. RevMan5.3 was used to assess the risk of bias.

Result

Six observational studies were assessed. The methodological quality of the trials indicated five of six studies had a low risk of bias and one article had a high risk of bias. The differences were statistically significant between AT and CT for HOS (follow-up for 6 months), iHOT-33 (follow-up for 6 months) improvement, iHOT-33 (follow-up for 12 months) improvement, iHOT-33 (follow-up for 12 months), EQ-5D-5L index score (follow-up for 12 months) and AT showed higher benefits than CT. Meanwhile no statistically significant were found in iHOT-33 (follow-up for 6 months), EQ-5D-5L index score (follow-up for 6 months), EQ5D-VAS (follow-up for 6 months) and EQ5D-VAS (follow-up for 12 months).

Conclusion

AT and CT both can have clinical effects when facing FAI. In our meta-analysis, hip arthroscopy is statistically superior to conservative treatment in both long-term and short-term effects.

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.

Acellular Matrix-Induced Chondrogenesis Technique Improves the Results of Chondral Lesions Associated With Femoroacetabular Impingement

PURPOSE

The study's main objective was to evaluate, in the short-term, the result of the autologous acellular matrix-induced chondrogenesis (AMIC) technique in a selected group of patients with 2-4 cm² full-thickness chondral lesions, undergoing hip arthroscopy for femoroacetabular impingement (FAI).

METHODS

A retrospective single-center Level IV case series of 25 patients (28 hips) who underwent an arthroscopic hip surgery with a liquid acellular collagen matrix. Inclusion criteria for implantation were FAI diagnosis (cam or pincer type), grade IV chondral lesions (Outerbridge size 2-4 cm²); Tönnis stage 0-II, minimum follow-up of 24 months, and 1 year (12-15 months) evaluation with very high field 3-T MRI arthrography. Exclusion criteria were Tönnis III, joint space <2 mm, center-edge angle <20°, and <24 months of follow-up. Clinical assessments involved symptoms duration until surgery, changes in physical and work activity and range of motion, modified Harris Hip Score, reporting percentages of patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID), pain with a VAS, and level of satisfaction. Radiological assessments: Tönnis stage, articular space, alpha and lateral center edge angle (Wiberg), and generated tissue characteristics at 1 year (based on the MOCART score), through 3-T MRI.

RESULTS

25 patients (28 hips) treated; 19 men and 6 women (mean age: 40.5 years; range: 25-55). Two women underwent joint replacement surgery. Thus, 23 patients (26 hips) were analyzed. At 29 months following surgery (range: 24-48), a significant improvement was obtained in all parameters assessed, focusing on the characteristics of the generated tissue in the MRI (MOCART scores). 95% of the patients met the MCID (improvement >12 points in the modified Harris Hip Score), and 100% scored >74 points, achieving the PASS. Patients' satisfaction was 86.6% (SD 16.4). All patients who practiced sports resumed them.

CONCLUSIONS

The liquid AMIC is a safe technique that shows good clinical and radiological outcomes in a 2-year follow-up in patients with femoroacetabular impingement and grade IV acetabular 2-4 cm² chondral defects.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Hip arthroscopy in osteoarthritis: Is it an option?

Arthritis of the hip is a degenerative disease characterised by pain and inflammation. It is common and most often affects middle-aged to older adults, with the definitive management being total hip replacement. Advances in the surgical techniques has brought about the popularity of hip preservation surgery in patients with pre-arthritic hip abnormalities, with a goal to prevent progression to early arthritis and subsequently prolong the need for arthroplasty. There is a large body of evidence correlating femoroacetabular impingement (FAI) and the progression of osteoarthritis. Hip arthroscopy is a successful technique in the management of FAI and labral damage. There is, however, less evidence behind its use in those patients with established arthritic changes. After review of such evidence, we believe hip arthroscopy, and other hip preservation procedures, have a key role, and should be considered in the management of early hip arthritis. However, there is no role for such procedures in end-stage arthritis.

Arthroscopic utilization of ChondroFiller gel for the treatment of hip articular cartilage defects: a cohort study with 12- to 60-month follow-up

ChondroFiller gel is an absorbable collagen implant. It serves as a protective cover for the cartilage defects, allowing chondrocyte migration into the lesion. The implant consists of collagen (Type I) and is derived from veterinary monitored rats. This study evaluates the use of ChondroFiller gel in the treatment of cartilage lesions during hip joint arthroscopy. A prospective study was conducted on a group of 26 adult patients. All patients had an existing femoroacetabular impingement together with acetabular cartilage lesions >2 cm². All patients underwent hip arthroscopic surgery and the lesions were treated using ChondroFiller gel. The cartilage tissue healing was evaluated postoperatively using MRI. A total of 26 patients, including 5 females and 21 males, all with articular cartilage lesions, were included in the study. Cartilage healing conditions were evaluated for all patients, and the difference between pre- and post-surgery conditions was statistically significant. The follow-up scores have been acquired from 21 out of initial 26 patients (2 were disqualified after receiving THR, 3 could not be reached by researchers) after 3, 4 and 5 years consecutively with 17/21 patients having good/excellent results. The use of ChondroFiller gel during arthroscopy of the hip for acetabular cartilage lesions is an effective treatment technique. Encouraging long-term results have been observed, but further research on larger group of patient is required to better assess the full value of this technique. Patients with pre-existing osteoarthritis (Tönnis 2–3) have poor results.

The correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients

BACKGROUND

Some studies have proved that labrum size is associated with symptoms in patients with hip labral tear. The correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients is still uncertain.

METHODS

The volunteers with no history of pain, injury, or surgery were recruited from the community. Patients who were diagnosed with labral tear and underwent hip arthroscopic surgery in this period in our hospital were also included. The length and height of the acetabular hip labrum were measured at three separate anatomic sites through magnetic resonance imaging (MRI) along the acetabular rim: lateral, anterior, and anteroinferior.

RESULTS

A total of 70 volunteers (125 hips) and 70 patients (70 hips) were included in this study. Sixty-six (52.8%) hips had labral tears in all 125 hips of volunteers. The lateral labral length of volunteers with labral tears was significantly larger than those without labral tears (P < .05). In 14 volunteers with unilateral labral tears, length of lateral, anterior, and anteroinferior labrum in the side with tear were significantly larger than normal on the other side. The anterior labral height of volunteers was significantly larger than that of patients (P < .05).

CONCLUSIONS

In conclusion, asymptomatic volunteers with larger length of lateral, anterior, and anteroinferior labrum are more prone to present with labral tears. Symptomatic patients with labral tears exhibited thinner anterior labrum. Further studies are warranted to explore the mechanisms of labral tears in asymptomatic people and validate the use of labral size as a guide to differential diagnosis and treatment.

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.

Revision Hip Arthroscopy in the Native Hip: A Review of Contemporary Evaluation and Treatment Options

Hip arthroscopy is a reproducible and efficacious procedure for the treatment of femoroacetabular impingement syndrome (FAIS). Despite this efficacy, clinical failures are observed, clinical entities are challenging to treat, and revision hip arthroscopy may be required. The most common cause of symptom recurrence after a hip arthroscopy that leads to a revision arthroscopy is residual cam morphology as a result of inadequate femoral osteochondroplasty and restoration of head–neck offset, though several other revision etiologies including progressive chondral and labral pathologies also exist. In these cases, it is imperative to perform a comprehensive examination to identify the cause of a failed primary arthroscopy as to assess whether or not a revision hip arthroscopy procedure is indicated. When a secondary procedure is indicated, approaches may consist of revision labral repair, complete labral reconstruction, or labral augmentation depending on labral integrity. Gross instability or imaging-based evidence of microinstability may necessitate capsular augmentation or plication. If residual cam or pincer morphology is present, additional resection of the osseous abnormalities may be warranted. This review article discusses indications, the evaluation of patients with residual symptoms after primary hip arthroscopy, and the evaluation of outcomes following revision hip arthroscopy through an evidence-based discussion. We also present a case example of a revision hip arthroscopy procedure to highlight necessary intraoperative techniques during a revision hip arthroscopy.

Hip Chondral Defects: Arthroscopic Treatment With the Needle and Curette Technique and ChondroFiller

Management of symptomatic focal cartilage defects of the hip can be challenging. Cells, scaffold therapies, and injectable agents have emerged as an adjunctive modality to improve clinical outcomes. Long and malleable needles that can be bent are used to release these kinds of biological products. Distance between the tip of the needle and the area to be filled should be minimal to ensure full contact with the chondral lesion to avoid losing material inside the hip cavity and to increase the efficiency of the release of the product. Nevertheless in many cases the accessibility is not easy, and the distance between the tip of the needle and the area to be treated is such that the efficiency of the release is difficult, if not impossible. We aim to describe a simple, inexpensive, and reproducible technique to facilitate the implantation of biologic and injectable materials in hip chondral defects during arthroscopy: the use of a combination of a curette and a needle inside the tip of the curette. Additionally we describe the use of ChondroFiller liquid, a liquid cell-free collagen matrix, for the treatment of symptomatic full-thickness chondral defects of the hip in a 1-step arthroscopic procedure.

Is there clinical evidence to support autologous matrix-induced chondrogenesis (AMIC) for chondral defects in the talus? A systematic review and meta-analysis

BACKGROUND

The aim of this study is to systematically review the literature on clinical outcomes of patients who have undergone autologous matrix-induced chondrogenesis (AMIC) for treatment of osteochondral lesions of the talus (OCL) and compare the studies' outcomes.

METHODS

Pubmed and Embase were searched in January 2020 for articles concerning OCL surgery. Studies were included if they had a minimum 1-year follow-up and the primary measures were functional outcomes. The meta-analysis compared the Visual Analogic Score (VAS), the American Orthopedic Foot and Ankle Score (AOFAS), and the Foot Function Index (FFI) between baseline and follow-up of 1-2years, and 3-5years. A random effects model was used to evaluate outcome changes.

RESULTS

The search returned 15 studies, with a total of 492 patients. The VAS improved 4.45 and 4.6 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). AOFAS improved 31.59 and 32.47 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). The FFI showed a significant improvement of 30.93 points from baseline to year 3-5 (p<0.001). A total of 6 patients with revision surgeries have been reported within the follow up period. It was not possible to correlate clinical features like lesion size, surgical approach, and bone marrow stimulation technique to the reported outcome.

CONCLUSION

Surgical treatment of OCL via the AMIC procedure provided significant improvement in the functional outcome and pain scores when compared to the pre-operative values. Improvements were observed up to 5years post-operatively.

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.

Autologous matrix-induced chondrogenesis and bone marrow aspirate concentrate compared with microfracture for arthroscopic treatment of femoroacetabular impingement and chondral lesions of the hip: bridging the osteoarthritis gap and facilitating enhanced recovery

In an attempt to bridge the osteoarthritis (OA) gap, this study compared biological reconstruction with traditional microfracture (MF) techniques in patients with femoroacetabular impingement and focal cartilage defects. Cohorts of two groups were investigated; age, gender and Tonnis grade matched comparison for outcomes between MF and newer biological reconstruction techniques hip arthroscopy surgery using autologous matrix-induced chondrogenesis and bone marrow aspirate combination. Outcomes investigated were pre-op and post-op mean iHOT-12 scores up to 18 months after surgery with a Kaplan–Meier survivorship analysis. Of 111 patients, 46 patients underwent MF and 65 biological reconstruction hip arthroscopy including cam/pincer osteoplasty and labral repair surgery. Age range was 20–69, mean age 45 years for both groups, Tonnis grading was as follows: Grade 0: 26% versus 30%, Grade 1: 52% versus 47% and Grade 2: 22% versus 23% in MF and biological reconstruction groups, respectively. The mean post-operative iHOT-12 score differences between MF and biological reconstruction were significant at 1-year minimum follow-up (P = 0.01, SD 2.8). Biological reconstruction allowed for an enhanced recovery protocol. The MF group had a 67.4% survivorship for conversion to hip replacement at 18 months (32.6% failure rate for any reason) and biological reconstruction had 100% survivorship at 18 months post-operatively with no failures for any reason. This study provides further support to the evidence base for biological reconstructive techniques as superior to MF in combination with joint preservation arthroscopic surgery, even in the face of focal cartilage defects and offers both surgeons and patients a potential bridging of the OA gap.

Sustained benefit of autologous matrix-induced chondrogenesis for hip cartilage repair in a recreational athletic population

PURPOSE

To investigate the clinical outcome of autologous matrix-induced chondrogenesis (AMIC) implementation for mid-sized chondral lesions of the acetabulum in young active patients, and assess their potential to resume an active lifestyle including return to recreational athletic activities.

METHODS

Sixty-two patients with full-thickness mid-sized acetabular chondral lesions were studied. All patients who underwent an arthroscopic AMIC procedure for reconstruction of chondral defects were assessed pre-operatively and at least 2 years post-operatively using the Hip disability and Osteoarthritis Outcome Score (HOOS), modified Harris Hip Score (mHHS) and Visual Analog Scale (VAS) for pain.

RESULTS

A significant improvement in all three scores at the time of follow-up was found. The mean HOOS improved from 58.8 ± 7.4 pre-operatively to 90.6 ± 7.1 at follow-up (p < 0.001) while the mean mHHS improved from 53.4 ± 6.6 to 82.4 ± 8.2 (p < 0.001). There was a significant decrease from 4.9 ± 1.1 pre-operatively to 1.1 ± 0.8 post-operatively (p < 0.001) in the VAS pain evaluation, indicating that the patients were satisfied with their relief of pain.

CONCLUSIONS

The AMIC procedure is an effective single-stage technique for the reconstruction of mid-size chondral defects of acetabulum in amateur athletes. This intervention enhanced the potential for patients to resume recreational athletic activities and the 2-year clinical outcome as evaluated by the HOOS, mHHS and VAS showed significant improvement over the pre-operative evaluations.

Small Subchondral Drill Holes Improve Marrow Stimulation of Rotator Cuff Repair in a Rabbit Model of Chronic Rotator Cuff Tear

BACKGROUND

Microfracture of the greater tuberosity has been proved effective for enhancing tendon-to-bone healing after rotator cuff repair. However, no standard diameter for the microfracture has been established.

PURPOSE/HYPOTHESIS

This study aimed to assess treatment with large- and small-diameter microfractures to enhance healing during rotator cuff repair surgery in a rabbit model of chronic rotator cuff tear. It was hypothesized that a small-diameter microfracture had advantages in terms of tendon-to-bone integration, bone-tendon interface maturity, microfracture healing, and biomechanical properties compared with a large-diameter microfracture.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bilateral supraspinatus tenotomy from the greater tuberosity was performed on 21 New Zealand White rabbits. Bilateral supraspinatus repair was performed 6 weeks later. Small-diameter (0.5 mm) microfracture and large-diameter microfracture (1 mm) were performed on the left side and right side, respectively, in 14 rabbits as a study group, and simple repair without microfracture was performed in 7 rabbits as a control group. At 12 weeks later, 7 of 14 rabbits in the study group were sacrificed for micro-computed tomography evaluation and biomechanical testing. Another 6 rabbits were sacrificed for histological evaluation. In the control group, 3 of the 7 rabbits were sacrificed for histological evaluation and the remaining rabbits were sacrificed for biomechanical testing.

RESULTS

Significantly better bone-to-tendon integration was observed in the small-diameter microfracture group. Better histological formation and maturity of the bone-tendon interface corresponding to better biomechanical results (maximum load to failure and stiffness) were obtained on the small-diameter microfracture side compared with the large-diameter side and the control group. The large-diameter microfracture showed worse radiographic and histological properties for healing of the microfracture holes on the greater tuberosity. Additionally, the large-diameter microfracture showed inferior biomechanical properties but similar histological results compared with the control group.

CONCLUSION

Small-diameter microfracture showed advantages with enhanced rotator cuff healing for biomechanical, histological, and radiographic outcomes compared with large-diameter microfracture, and large-diameter microfracture may worsen the rotator cuff healing.

CLINICAL RELEVANCE

This animal study suggested that a smaller diameter microfracture may be a better choice to enhance healing in clinical rotator cuff repair surgery in humans.

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.