Chemoprophylaxis for heterotopic ossification following hip arthroscopy: A systematic review.

INTRODUCTION: Heterotopic ossification (HO) is a known complication diagnosed following hip arthroscopy. PURPOSE/HYPOTHESIS: This study sought to review the current literature on chemoprophylaxis for HO following hip arthroscopy and to describe what agents and doses are being utilized. STUDY DESIGN: Systematic Review. METHODS: A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines on the use of chemoprophylactic medications for HO prevention following hip arthroscopy. Mechanical and radiation prophylaxis were not included in the current analysis. RESULTS: A total of 203 studies were identified, of which 15 were included with 6463 patients. There was one randomized control trial (RCT) and 4 additional comparative studies. The most commonly utilized chemoprophylactic agents were the following: naproxen (n â€‹= â€‹8), celecoxib (n â€‹= â€‹3), indomethacin (n â€‹= â€‹3), aspirin (n â€‹= â€‹1), etoricoxib (n â€‹= â€‹1), and etodolac (n â€‹= â€‹1), and non-specific non-steroidal anti-inflammatory drugs (NSAIDs) (n â€‹= â€‹1). Naproxen was either given at a dose of 500 â€‹mg once or twice daily for 2-4 weeks. RCTs and additional comparative studies showed significant HO prevention using chemoprophylactic agents following hip arthroscopy. CONCLUSIONS: HO is a known and common complication following hip arthroscopy. The current systematic review found significant heterogeneity across the literature with respect to specific chemoprophylactic agents and their dosing regimens aimed to reduce the incidence and severity of HO following hip arthroscopy. Additionally, this review demonstrates that most studies that utilize chemoprophylaxis use NSAIDs with successful reduction in the incidence of HO. LEVEL OF EVIDENCE: Level IV Evidence.

Medial Patellofemoral Ligament Reconstruction in Obese Patients Results in Low Complication Rates and Improved Subjective Outcomes.

Purpose: To compare outcomes, activity scores, and complication rates of obese and non-obese patients undergoing medial patellofemoral ligament (MPFL) reconstruction. Methods: A retrospective review identified patients undergoing MPFL reconstruction for recurrent patellofemoral instability. Patients were included if they had undergone MPFL reconstruction and had follow-up for a minimum of 6 months. Patients were excluded if they underwent surgery less than 6 months earlier, had no outcome data recorded, or underwent concomitant bony procedures. Patients were divided into 2 groups based on body mass index (BMI): BMI of 30 or greater and BMI less than 30. Presurgical and postsurgical patient-reported outcomes including Knee Injury and Osteoarthritis Outcome Score (KOOS) domains and the Tegner score were collected. Complications requiring reoperation were recorded. P < .05 was defined as a statistically significant difference. Results: A total of 55 patients (57 knees) were included. There were 26 knees with a BMI of 30 or greater and 31 knees with a BMI less than 30. There were no differences in patient demographic characteristics between the 2 groups. Preoperatively, no significant differences were found in KOOS subscores or Tegner scores (P = .21) between groups. At minimum 6-month follow-up (range, 6.1-70.5 months), patients with a BMI of 30 or greater showed statistically significant improvements in the KOOS Pain, Activities of Daily Living, Symptoms, and Sport/Recreation subscores. Patients with a BMI less than 30 showed a statistically significant improvement in the KOOS Quality of Life subscore. The group with a BMI of 30 or greater had significantly lower KOOS Quality of Life (33.34 ± 19.10 vs 54.47 ± 28.00, P = .03) and Tegner (2.56 ± 1.59 vs 4.78 ± 2.68, P = .05) scores. Complication rates were low, with 2 knees (7.69%) requiring reoperation in the cohort with a BMI of 30 or greater and 4 knees (12.90%) requiring reoperation in the cohort with a BMI less than 30, including 1 reoperation for recurrent patellofemoral instability (P = .68). Conclusions: In this study, MPFL reconstruction in obese patients was safe and effective, with low complication rates and improvements in most patient-reported outcomes. Compared with patients with a BMI less than 30, obese patients had lower quality-of-life and activity scores at final follow-up. Level of Evidence: Level III, retrospective cohort study.

Magnetic resonance imaging overestimates patellar height compared with radiographs.

PURPOSE: To evaluate the inter-observer and inter-method reliability for patellar height measurements between conventional radiographs (CR) and magnetic resonance imaging (MRI) using one or two slices. METHODS: This was a reliability study, with 60 patients divided in two groups: 30 patients with patellar instability (patella group) and 30 patients with anterior cruciate ligament or meniscus injury (control group). CR and MRI were evaluated by two independent observers. Insall-Salvati index (IS) and Caton-Deschamps index (CD) were measured using three different methods: CR, one-slice MRI or two-slice MRI. Intra-class correlation coefficients (ICC) were calculated for inter-observer reliability and inter-method reliability. Bland-Altman agreement was also calculated. RESULTS: The inter-observer reliability was very good for the IS with ICCs of 0.93, 0.84 and 0.82, for the CR, one-slice MRI and two-slice MRI, respectively. Similarly, for the CD the ICCs were good, 0.76, 0.80 and 0.75 for the CR, one-slice MRI and two-slice MRI, respectively. No differences were found between the patella and the control group. The inter-method analysis results were: ICCs for IS (0.83, 0.86, 0.93) and CD (0.72, 0.82, 0.83), for the comparisons of CR/one-slice MR, CR/two-slice MRI and one-slice MRI/two-slice MRI, respectively. The Bland-Altman mean differences showed an 8% and a 7% increase on IS values with one-slice MRI and two-slice MRI compared to CR results, while the increase was of 9% and 1% in CD for the respective comparisons with CR. CONCLUSION: MRI can overestimate patellar height compared to CR, as much as an 8% increase in Insall-Salvati values when using one- or two-slice MRI measurements, and up to a 9% increase in Caton-Deschamps value when using the one-slice MRI method. It is recommended to use the CR as the preferred method when measuring patellar height. LEVEL OF EVIDENCE: III.

Conversion rates and timing to total knee arthroplasty following anterior cruciate ligament reconstruction: a US population-based study.

PURPOSE: To define the rate of subsequent TKA following ACLR in a large US cohort and to identify factors that influence the risk of later undergoing TKA after ACLR. METHODS: The California's Office of Statewide Health Planning and Development (OSHPD) database was queried from 2000 to 2014 to identify patients who underwent primary ACLR (ACL group). An age-and gender-matched cohort that underwent appendectomy was selected as the control group. The cumulative incidence of TKA was calculated and ten-year survival was investigated using Kaplan-Meier analysis with failure defined as conversion to arthroplasty. Univariate and multivariate analyses were performed to explore the risk factors for conversion to TKA following ACLR. RESULTS: A total of 100,580 ACLR patients (mean age 34.48 years, 66.1%male) were matched to 100,545 patients from the general population. The ACL cohort had 1374 knee arthroplasty events; conversion rate was 0.71% at 2-year follow-up, 2.04% at 5-year follow-up, and 4.86% at 10-year follow-up. This conversion rate was higher than that of the control group at all time points, with an odds ratio of 3.44 (p<0.001) at 10-year follow-up. Decreasing survivorship following ACLR was observed with increasing age, female gender, and worker's compensation insurance, while increased survivorship was found in patients of Hispanic and Asian Pacific Islander racial heritage and those who underwent concomitant meniscal repair. CONCLUSIONS: In this US statewide study, the rate of TKA after ACLR is higher than reported elsewhere, with significantly increased odds when compared to a control group. Age, gender, concomitant knee procedures and other socioeconomic factors influence the rate of conversion to TKA following ACLR.

Evaluation of Commercially Available Knee Cartilage Restoration Techniques Stratified by FDA Approval Pathway.

BACKGROUND: Commercially available products used in knee cartilage reconstructive and restorative surgical practices fall under unique US Food and Drug Administration (FDA) regulatory pathways that determine the level of evidence required to market each product. PURPOSE: To evaluate the levels of evidence in the literature supporting commercially available cartilage repair procedures stratified by FDA regulatory pathway (section 351 vs section 361 of "Human Cells, Tissues, and Cellular and Tissue-Based Products" [HCT/P] in the Code of Federal Regulation) with the hypothesis that products requiring approval under a stringent regulatory pathway (351 HCT/P) have higher levels of evidence in the literature supporting use and that products with a less stringent regulatory pathway (361 HCT/P) have a higher number of products available for use in the United States. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A search of the PubMed database was performed to identify all peer-reviewed articles pertaining to either allograft or autologous cartilage repair technologies. Predefined inclusion and exclusion criteria were used to find clinical, preclinical, and laboratory studies while excluding duplicates, systematic reviews, and products not available in the United States. Articles were categorized by regulatory pathway (351 and 361 HCT/P), and variables including publication year, type of publication, level of evidence, and number of publications were analyzed. RESULTS: After application of predefined criteria, 470 of 1924 articles were included in this study. The 351 HCT/P group was composed entirely of autologous chondrocyte implantation (ACI) technology; 94% of the 361 HCT/P group was composed of osteochondral allografts (OCA). The articles regarding 351 HCT/P were more likely to be clinical in nature than the articles on 361 HCT/P (80% vs 48%, respectively; P = .0001) and entailed significantly more level 1 studies (25 vs 0, respectively; P < .0001). Twice as many articles in the 351 HCT/P group were published in the American Journal of Sports Medicine compared with the 361 HCT/P group (71 vs 38, respectively; P = .18). CONCLUSION: Both ACI and OCA have robust evidence supporting their use, whereas the remaining regulated products have little or no supporting evidence. Technologies regulated by 351 HCT/P were more likely to be level 1 clinical studies and published in the highest impact journal. The 361 HCT/P pathway regulated many more products, with fewer articles supporting their use.

Algorithm for Treatment of Focal Cartilage Defects of the Knee: Classic and New Procedures.

OBJECTIVE: To create a treatment algorithm for focal grade 3 or 4 cartilage defects of the knee using both classic and novel cartilage restoration techniques. DESIGN: A comprehensive review of the literature was performed highlighting classic as well as novel cartilage restoration techniques supported by clinical and/or basic science research and currently being employed by orthopedic surgeons. RESULTS: There is a high level of evidence to support the treatment of small to medium size lesions (<2-4 cm2) without subchondral bone involvement with traditional techniques such as marrow stimulation, osteochondral autograft transplant (OAT), or osteochondral allograft transplant (OCA). Newer techniques such as autologous matrix-induced chondrogenesis and bone marrow aspirate concentrate implantation have also been shown to be effective in select studies. If subchondral bone loss is present OAT or OCA should be performed. For large lesions (>4 cm2), OCA or matrix autologous chondrocyte implantation (MACI) may be performed. OCA is preferred over MACI in the setting of subchondral bone involvement while cell-based modalities such as MACI or particulated juvenile allograft cartilage are preferred in the patellofemoral joint. CONCLUSIONS: Numerous techniques exist for the orthopedic surgeon treating focal cartilage defects of the knee. Treatment strategies should be based on lesion size, lesion location, subchondral bone involvement, and the level of evidence supporting each technique in the literature.

Acute Patellofemoral Dislocation: Controversial Decision-Making.

PURPOSE OF REVIEW: The topic of acute patella dislocations is controversial. Discussions revolve around which individuals need early surgery, identification of risk factors, and rehabilitation protocol. The purpose of this review is to discuss the current recommendations for non-operative and/or operative management of first-time dislocators. RECENT FINDINGS: Recent studies have made it clear that not all patellar dislocations are the same, not all patients do well with conservative treatment, and risk stratification can identify individuals at high risk of recurrence who would benefit from early surgical intervention. Risk factors that have been identified include younger age, skeletally immature, contralateral instability, trochlear dysplasia, patella alta, increased tibial tubercle-trochlear groove distance, and increased patella tilt. The PAPI (Pediatric and Adolescent Patellar Instability) RCT study and JUPITER (Justifying Patellar Instability Treatment by Early Results) prospective cohort study have been carefully developed, are under way, and will provide further guidance. In summary, the management of acute patellar dislocations is evolving. Surgery for patients with osteochondral loose bodies should include fixation as well as soft tissue stabilization. The standard of care for patients with an acute patellar dislocation without osteochondral loose bodies or fracture is non-operative treatment. However, imaging for all first-time dislocators is indicated to stratify risks and determine risk profile. If an individual is at high risk, soft tissue stabilization may be considered. Still, most patients will be treated non-operatively.

Accurate Reporting of Concomitant Procedures Is Highly Variable in Studies Investigating Knee Cartilage Restoration.

OBJECTIVE: Successful clinical outcomes following cartilage restoration procedures are highly dependent on addressing concomitant pathology. The purpose of this study was to document methods for evaluating concomitant procedures of the knee when performed with articular cartilage restoration techniques, and to review their reported findings in high-impact clinical orthopedic studies. We hypothesized that there are substantial inconsistencies in reporting clinical outcomes associated with concomitant procedures relative to outcomes related to isolated cartilage repair. DESIGN: A total of 133 clinical studies on articular cartilage repair of the knee were identified from 6 high-impact orthopedic journals between 2011 and 2017. Studies were included if they were primary research articles reporting clinical outcomes data following surgical treatment of articular cartilage lesions with a minimum sample size of 5 patients. Studies were excluded if they were review articles, meta-analyses, and articles reporting only nonclinical outcomes (e.g., imaging, histology). A full-text review was then used to evaluate details regarding study methodology and reporting on the following variables: primary cartilage repair procedure, and the utilization of concomitant procedures to address additional patient comorbidities, including malalignment, meniscus pathology, and ligamentous instability. Each study was additionally reviewed to document variation in clinical outcomes reporting in patients that had these comorbidities addressed at the time of surgery. RESULTS: All studies reported on the type of primary cartilage repair procedure, with autologous chondrocyte implantation (ACI) noted in 43% of studies, microfracture (MF) reported in 16.5%, osteochondral allograft (OCA) in 15%, and osteochondral autograft transplant (OAT) in 8.2%. Regarding concomitant pathology, anterior cruciate ligament (ACL) reconstruction (24.8%) and meniscus repair (23.3%) were the most commonly addressed patient comorbidities. A total of 56 studies (42.1%) excluded patients with malalignment, meniscus injury, and ligamentous instability. For studies that addressed concomitant pathology, 72.7% reported clinical outcomes separately from the cohort treated with only cartilage repair. A total of 16.5% of studies neither excluded nor addressed concomitant pathologies. There was a significant amount of variation in the patient reported outcome scores used among the studies, with the majority of studies reporting International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcomes Score (KOOS) in 47.2% and 43.6% of articles, respectively. CONCLUSIONS: In this study on knee cartilage restoration, recognition and management of concomitant pathology is inadequately reported in approximately 28% of studies. Only 30% of articles reported adequate treatment of concomitant ailments while scoring their outcomes using one of a potential 18 different scoring systems. These findings highlight the need for more standardized methods to be applied in future research with regard to inclusion, exclusion, and scoring concomitant pathologies with regard to treatment of cartilage defects in the knee.

Cartilage Restoration of Patellofemoral Lesions: A Systematic Review.

PURPOSE: This study aimed to systematically analyze the postoperative clinical, functional, and imaging outcomes, complications, reoperations, and failures following patellofemoral cartilage restoration surgery. METHODS: This review was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed, EMBASE, and Cochrane Library databases were searched up to August 31, 2018, to identify clinical studies that assessed surgical outcomes of patellofemoral cartilage restoration surgery. The Methodological Index for Non-Randomized Studies (MINORS) was used to assess study quality. RESULTS: Forty-two studies were included comprising 1,311 knees (mean age of 33.7 years and 56% males) and 1,309 patellofemoral defects (891 patella, 254 trochlear, 95 bipolar, and 69 multiple defects, including the patella or trochlea) at a mean follow-up of 59.2 months. Restoration techniques included autologous chondrocyte implantation (56%), particulated juvenile allograft cartilage (12%), autologous matrix-induced chondrogenesis (9%), osteochondral autologous transplantation (9%), and osteochondral allograft transplantation (7%). Significant improvement in at least one score was present in almost all studies and these surpassed the minimal clinically important difference threshold. There was a weighted 19%, 35%, and 6% rate of reported complications, reoperations, and failures, respectively. Concomitant patellofemoral surgery (51% of patients) mostly did not lead to statistically different postoperative outcomes. CONCLUSION: Numerous patellofemoral restoration techniques result in significant functional improvement with a low rate of failure. No definitive conclusions could be made to determine the best surgical technique since comparative studies on this topic are rare, and treatment choice should be made according to specific patient and defect characteristics. LEVEL OF EVIDENCE: Level IV, systematic review of level II to IV studies.

An Expert Consensus Statement on the Management of Large Chondral and Osteochondral Defects in the Patellofemoral Joint.

BACKGROUND: Cartilage lesions of the patellofemoral joint constitute a frequent abnormality. Patellofemoral conditions are challenging to treat because of complex biomechanics and morphology. PURPOSE: To develop a consensus statement on the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint using a modified Delphi technique. STUDY DESIGN: Consensus statement. METHODS: A working group of 4 persons generated a list of statements related to the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint to form the basis of an initial survey for rating by a group of experts. The Metrics of Osteochondral Allografts (MOCA) expert group (composed of 28 high-volume cartilage experts) was surveyed on 3 occasions to establish a consensus on the statements. In addition to assessing agreement for each included statement, experts were invited to propose additional statements for inclusion or to suggest modifications of existing statements with each round. Predefined criteria were used to refine statement lists after each survey round. Statements reaching a consensus in round 3 were included within the final consensus document. RESULTS: A total of 28 experts (100% response rate) completed 3 rounds of surveys. After 3 rounds, 36 statements achieved a consensus, with over 75% agreement and less than 20% disagreement. A consensus was reached in 100.00% of the statements relating to functional anatomy of the patellofemoral joint, 88.24% relating to surgical indications, 100.00% relating to surgical technical aspects, and 100.00% relating to rehabilitation, with an overall consensus of 95.5%. CONCLUSION: This study established a strong expert consensus document relating to the functional anatomy, surgical indications, donor graft considerations for osteochondral allografts, surgical technical aspects, and rehabilitation concepts for the management of large chondral and osteochondral defects in the patellofemoral joint. Further research is required to clinically validate the established consensus statements and better understand the precise indications for surgery as well as which techniques and graft processing/preparation methods should be used based on patient- and lesion-specific factors.

Patellofemoral Cartilage Restoration: A Systematic Review and Meta-analysis of Clinical Outcomes.

BACKGROUND: Many surgical options for treating patellofemoral (PF) cartilage lesions are available but with limited evidence comparing their results. PURPOSE: To determine and compare outcomes of PF cartilage restoration techniques. STUDY DESIGN: Systematic review and meta-analysis. METHODS: PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines were followed by utilizing the PubMed, EMBASE, and Cochrane Library databases. Inclusion criteria were clinical studies in the English language, patient-reported outcomes after PF cartilage restoration surgery, and >12 months' follow-up. Quality assessment was performed with the Coleman Methodology Score. Techniques were grouped as osteochondral allograft transplantation (OCA), osteochondral autograft transfer (OAT), chondrocyte cell-based therapy, bone marrow-based therapy, and scaffolds. RESULTS: A total of 59 articles were included. The mean Coleman Methodology Score was 71.8. There were 1937 lesions (1077 patellar, 390 trochlear, and 172 bipolar; 298 unspecified). The frequency of the procedures was as follows, in descending order: chondrocyte cell-based therapy (65.7%), bone marrow-based therapy (17.2%), OAT (8%), OCA (6.6%), and scaffolds (2.2%). When compared with the overall pooled lesion size (3.9 cm2; 95% CI, 3.5-4.3 cm2), scaffold (2.2 cm2; 95% CI, 1.8-2.5 cm2) and OAT (1.5 cm2; 95% CI, 1.1-1.9 cm2) lesions were smaller (P < .001), while chondrocyte cell-based therapy lesions were larger (4.7 cm2; 95% CI, 4.1-5.3 cm2; P = .039). Overall, the instability pool was 11.9%, and the anatomic risk factors pool was 32.1%. Statistically significant improvement was observed on at least 1 patient-reported outcome in chondrocyte cell-based therapy (83%), OAT (78%), OCA (71%), bone marrow-based therapy (64%), and scaffolds (50%). There were no significant differences between any group and the overall pooled change in International Knee Documentation Committee score (30.2; 95% CI, 27.4-32.9) and Lysholm score (25.2; 95% CI, 16.9-33.5). There were no significant differences between any group and the overall pooled rate in minor complication rate (7.6%; 95% CI, 4.7%-11.9%) and major complication rate (8.3%; 95% CI, 5.7%-12.0%); however, OCA had a significantly greater failure rate (22.7%; 95% CI, 14.6%-33.4%) as compared with the overall rate (6.8%; 95% CI, 4.7%-9.5%). CONCLUSION: PF cartilage restoration leads to improved clinical outcomes, with low rates of minor and major complications. There was no difference among techniques; however, failures were higher with OCA.

Evidence-based Risk Stratification for Sport Medicine Procedures During the COVID-19 Pandemic.

Orthopaedic practices have been markedly affected by the emergence of the COVID-19 pandemic. Despite the ban on elective procedures, it is impossible to define the medical urgency of a case solely on whether a case is on an elective surgery schedule. Orthopaedic surgical procedures should consider COVID-19-associated risks and an assimilation of all available disease dependent, disease independent, and logistical information that is tailored to each patient, institution, and region. Using an evidence-based risk stratification of clinical urgency, we provide a framework for prioritization of orthopaedic sport medicine procedures that encompasses such factors. This can be used to facilitate the risk-benefit assessment of the timing and setting of a procedure during the COVID-19 pandemic.

A new device for patellofemoral instrumented stress-testing provides good reliability and validity.

PURPOSE: To evaluate the reliability of an instrumented patellofemoral (PF) stress-testing-the Porto Patellofemoral Testing Device (PPTD)-and validate the instrumented assessment method comparing to manual physical examination. METHODS: Eight asymptomatic volunteers underwent bilateral PF-instrumented examination with the PPTD and magnetic resonance imaging (MRI) to assess intra-rater reliability of the instrumented assessment methodology. Six patients with unilateral PF instability underwent physical examination and PPTD concomitantly with MRI. Manual examination was performed by two blinded surgeons and compared with PPTD test. Ligament stiffness was calculated and compared between injured and non-injured lower limbs. RESULTS: PPTD showed a pre-determined and reproducible stress-force application with excellent intra-rater agreement (intra-class correlation coefficient 0.83-0.98). The manual exam was imprecise with variable examiner-dependent stress-force application. The PPTD resulted in greater lateral patellar translation (converted in quadrants) than manual exam for patients that have reached maximum translation force. Measurement of patellar position and displacement using PPTD was more accurate and precise than the visual estimation of translated quadrants by manual exam. Ligament stiffness curves showed no relevant changes in patellar displacement after 62 N. CONCLUSION: The PPTD instrumented stress-testing is a valid device to quantify PF position and displacement with high intra-rater reliability, showing more accuracy, more precision and less variability than physical examination. This device provides an accurate and objective measure to quantify the patellar movement which can augment the physical examination procedures and assist clinicians in the management of decision-making and in the assessment of post-treatment outcomes of PF pathological conditions.

Concepts of the Distal Medial Patellar Restraints: Medial Patellotibial Ligament and Medial Patellomeniscal Ligament.

The important medial patellar ligamentous restraints to lateral dislocation are the proximal group (the medial quadriceps tendon femoral ligament and the medial patellofemoral ligament) and the distal group [medial patellotibial ligament (MPTL) and medial patellomeniscal ligament (MPML)]. The MPTL patellar insertion is at inferomedial border of patella and tibial insertion is in the anteromedial tibia. The MPML originates in the inferomedial patella, right proximal to the MPTL, inserting in the medial meniscus. On the basis of anatomy and biomechanical studies, the MPTL and MPML are more important in 2 moments during knee range of motion: terminal extension, when it directly counteracts quadriceps contraction. In a systematic review on MPTL reconstructions 19 articles were included detailing the clinical outcomes of 403 knees. All were case series. Overall, good and excellent outcomes were achieved in >75% of cohorts in most studies and redislocations were <10%, with or without the association of the medial patellofemoral ligament. The MPTL is a relevant additional tool to proximal restraint reconstruction in select patient profiles; however, more definitive clinical studies are necessary to better define surgical indications.

When to Add Lateral Soft Tissue Balancing?

Lateral patellofemoral (PF) soft tissue abnormalities range from excessive lateral PF tightness (lateral patellar compression syndrome, lateral patellar instability and arthritis), to excessive laxity (iatrogenic lateral PF soft tissue insufficiency postlateral release). The lateral soft tissue complex is composed of the iliotibial band extension to the patella, the vastus lateralis tendon, the lateral PF ligament, lateral patellotibial ligament, and lateral patellomeniscal ligament, with intimate connections between those structures. To identify lateral retinaculum tightness or insufficiency the most important tests are the patellar glide test and patellar tilt test. Imaging aids in that evaluation relying mostly on the patella position assessed by radiographs, computed tomography, and magnetic resonance imaging with referencing to the posterior femoral condyles. Lateral retinaculum lengthening (preferred) or release may be added when there is excessive lateral retinaculum tightness. A lengthening may be performed using a minimally invasive approach without compromising the lateral patella restraint. Lateral retinaculum repair or reconstruction is indicated when there is lateral retinaculum insufficiency. Lateral retinaculum surgery to balance the medial/lateral soft tissue restraints, improves patellar positioning and clinical results.

Anatomic Risk Factors for Focal Cartilage Lesions in the Patella and Trochlea: A Case-Control Study.

BACKGROUND: Focal cartilage lesions in the patellofemoral (PF) joint are common. Several studies correlated PF risk factors with PF instability, anterior knee pain, and PF arthritis; however, there is a lack of evidence correlating those factors to PF focal cartilage lesions. PURPOSE: To evaluate the influence of the anatomic PF risk factors in patients with isolated focal PF cartilage lesions. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Patients with isolated PF focal cartilage lesions were included in the cartilage lesion group, and patients with other pathologies and normal PF cartilage were included in the control group. Multiple PF risk factors were accessed on magnetic resonance imaging scans: patellar morphology (patellar width, patellar thickness, and patellar angle), trochlear morphology (trochlear sulcus angle, lateral condyle index, and trochlear sulcus depth), patellar height (Insall-Salvati ratio and Caton-Deschamps index), axial patellar positioning (patellar tilt, angle of Fulkerson), and quadriceps vector (tibial tuberosity-trochlear groove distance). RESULTS: A total of 135 patients were included in the cartilage lesion group and 100 in the control group. As compared with the control group, the cartilage lesion group had a higher sulcus angle (P = .0007), lower trochlear sulcus depth (P < .0001), lower angle of Fulkerson (P < .0001), lower patellar width (P = .0003), and higher Insall-Salvati ratio (P < .0001). From the patients in the cartilage lesion group, 36% had trochlear dysplasia; 27.6%, patella alta; and 24.7%, abnormal patellar tilt. These parameters were more frequent in the cartilage lesion group (P < .0001). Trochlear lesions were more frequent in men, presented at an older age, and had fewer associated anatomic risk factors. Patellar lesions, conversely, were more frequent in women, presented at younger age, and were more closely associated with anatomic risk factors. CONCLUSION: PF anatomic abnormalities are significantly more common in patients with full-thickness PF cartilage lesions. Trochlear dysplasia, patella alta, and excessive lateral patellar tilt are the most common correlated factors, especially in patellar lesions.

The Role of Bone Marrow Aspirate Concentrate for the Treatment of Focal Chondral Lesions of the Knee: A Systematic Review and Critical Analysis of Animal and Clinical Studies.

PURPOSE: To summarize currently available data regarding the use of bone marrow aspirate concentrate (BMAC) for the treatment of focal chondral lesions of the knee in experimental animal models and human clinical studies. METHODS: A systematic review searching for the terms "(bone marrow)" AND "(aspirate OR concentrate)" AND "(cartilage OR chondral OR osteochondral)" was performed in the databases PubMed, Cochrane Central Register of Controlled Trials, and Google Scholar regarding the use of BMAC for the treatment of focal chondral lesions of the knee. The inclusion criteria were animal and clinical studies published in English that used autologous BMAC to treat focal chondral defects of the knee. We excluded studies that evaluated nonconcentrated preparations of bone marrow aspirate or preparations that were culture expanded. RESULTS: A total of 23 studies were included: 10 studies performed in animal models and 13 human clinical studies. Animal studies showed inconsistent outcomes regarding the efficacy of BMAC for the treatment of chondral or osteochondral lesions, assessed by gross morphology, second-look arthroscopy, magnetic resonance imaging, histology, immunohistochemistry, mechanical testing, and micro-tomography. Chondral defect filling was achieved with fibrocartilage or "hyaline-like" cartilage. Cells present in BMAC did not meet the criteria to be characterized as mesenchymal stem cells according to the International Society for Cell Therapy because freshly isolated cells failed to show tri-lineage differentiation. Overall, all clinical studies, independent of the study group or level of evidence, reported improved clinical outcomes and higher macroscopic, magnetic resonance imaging, and histology scores. Comparative trials favored BMAC over microfracture and reported equivalent outcomes between BMAC and matrix-induced autologous chondrocyte implantation. However, clinical studies were scant and showed low scientific rigor, poor methodologic quality, and low levels of evidence on average. CONCLUSIONS: Although clinical success in short-term and midterm applications has been suggested for the application of BMAC for the restoration of cartilage defects in lesions of the knee, current study designs are generally of low scientific rigor. In addition, clinical applications of this technology in animal model investigations have shown inconsistent outcomes. Thus, clinicians should apply this technology cautiously. LEVEL OF EVIDENCE: Level IV, systematic review of Level II, III, and IV evidence studies.

Articular Cartilage Lesion Characteristic Reporting Is Highly Variable in Clinical Outcomes Studies of the Knee.

OBJECTIVE: The purpose of this study was to investigate the degree of standardized evaluation and reporting of cartilage lesion characteristics in high-impact clinical studies for symptomatic lesions of the knee. We hypothesized that there are significant inconsistencies in reporting these metrics across orthopedic literature. DESIGN: A total of 113 clinical studies on articular cartilage restoration of the knee were identified from 6 high-impact orthopedic journals between 2011 and 2016. Full-text review was used to evaluate sources for details on study methodology and reporting on the following variables: primary procedure, location, size, grade, and morphology of cartilage lesions. RESULTS: All studies reported on the type of primary cartilage procedure and precise lesion location(s). Approximately 99.1% reported lesion morphology (chondral, osteochondral, mixed). For lesion size, 32.7% of articles did not report how size was measured and 11.5% did not report units. The lesion sizing method was variable, as 27.4% used preoperative magnetic resonance imaging to measure/report lesion size, 31.0% used arthroscopy, and 8.8% used both. The majority of studies (83.2%) used area to report size, and 5.3% used diameter. Formal grading was not reported in 17.7% of studies. Only 54.8% of studies reported depth when sizing osteochondral defects. CONCLUSIONS: Recent literature on cartilage restoration provides adequate information on surgical technique, lesion location, and morphology. However, there is wide variation and incomplete reporting on lesion size, depth, and grading. Future clinical studies should include these important data in a consistent manner to facilitate comparison among surgical techniques.

Reconstruction of the medial patellotibial ligament results in favorable clinical outcomes: a systematic review.

PURPOSE: The medial patellotibial ligament (MPTL), the medial patellofemoral ligament (MPFL), and the medial patellomeniscal ligament (MPML) support the stability of the patellofemoral joint. The purpose of this systematic review was to report the surgical techniques and clinical outcomes of the repair or reconstruction of the MPTL in isolation or concomitant with the MPFL and/or other procedures. METHODS: A systematic review of the literature was conducted. Inclusion criteria were articles in the English language that reported clinical outcomes of the reconstruction of the MPTL in isolation or in combination with the MPFL and/or other procedures. Included articles were then cross-referenced to find additional journal articles not found in the initial search. The methodological quality of the articles was determined using the Coleman Methodology Score. RESULTS: Nineteen articles were included detailing the clinical outcomes of 403 knees. The surgical procedures described included hamstrings tenodesis with or without other major procedures, medial transfer of the medial patellar tendon with or without other major procedures and the reconstruction of the MPTL in association with the MPFL. Overall, good and excellent outcomes were achieved in > 75% of cohorts in most studies and redislocations were < 10%, with or without the association of the MPFL. An exception was one study that reported a high failure rate of 82%. Results were consistent across different techniques. The median CMS for the articles was 66 out of 100 (range 30-85). CONCLUSION: Across different techniques, the outcomes are good with low rates of recurrence, with one article reporting a high rate of recurrence. Quality of the articles is variable, from low to high. Randomized control trials are needed for a better understanding of the indications, surgical techniques, and clinical outcomes. This systematic review suggests that the reconstruction of the MPTL leads to favorable clinical outcomes and supports the role of the procedure as a valid surgical patellar stabilization procedure. LEVEL OF EVIDENCE: IV: systematic review of level I-IV studies.

Patellofemoral Cartilage Restoration: Indications, Techniques, and Outcomes of Autologous Chondrocytes Implantation, Matrix-Induced Chondrocyte Implantation, and Particulated Juvenile Allograft Cartilage.

Focal chondral defects are common in the patellofemoral (PF) joint and can significantly impair the quality of life. The autologous chondrocytes implantation (ACI) technique has evolved over the past 20 years: the first-generation technique involves the use of a periosteal patch, the second-generation technique (collagen-cover) uses a type I/III collagen membrane, and the newest third-generation technique seeds and cultivates the collagen membrane with chondrocytes prior to implantation and is referred to as matrix-induced autologous chondrocyte implantation. Particulated juvenile allograft cartilage (PJAC) (DeNovo NT) is minced cartilage allograft from juvenile donors. A thorough physical exam is important, especially for issues affecting the PF joint, to isolate the location and source of pain, and to identify associated pathologies. Imaging studies allow further characterization of the lesions and identification of associated pathologies and alignment. Conservative management should be exhausted before proceeding with surgical treatment. Steps of surgical treatment are diagnostic arthroscopy and biopsy, chondrocytes culture and chondrocyte implantation for the three generations of ACI, and diagnostic arthroscopy and implantation for PJAC. The techniques and their outcomes will be discussed in this article.