Factores etiopatogénicos y tratamiento de la enfermedad de Müller-Weiss / Etiopathogenic factors and treatment of Müller-Weiss disease

Antecedentes y objetivo: La enfermedad de Müller-Weiss (EMW) es una anomalía poco frecuente del escafoides tarsiano. Maceira y Rochera propusieron la teoría etiopatogénica más comúnmente aceptada, en la que estarían implicados factores displásicos, mecánicos y ambientales socioeconómicos. Se pretende describir las características clínicas y sociodemográficas de los pacientes de nuestro entorno con EMW, corroborar su asociación con los factores socioeconómicos descritos previamente, estimar la influencia de otros factores descritos en el desarrollo de la EMW, así como describir el tratamiento realizado. Materiales y métodos: Estudio retrospectivo de 60 pacientes diagnosticados de EMW en 2 hospitales terciarios de Valencia (España) entre los años 2010 y 2021. Resultados: Se incluyeron 60 pacientes, 21 (35,0%) hombres y 39 (65,0%) mujeres. En 29 (47,5%) casos la afectación fue bilateral. La media de edad de inicio de la sintomatología fue de 41,9±20,3 años. Durante la infancia, 36 (60,0%) pacientes sufrieron movimientos migratorios, y 26 (43,3%) problemas dentarios. La edad media de inicio laboral fue de 14,6±4,5 años. Se trataron de forma ortopédica 35 (58,3%) casos frente a 25 (41,7%) tratados quirúrgicamente, 11 (18,3%) mediante osteotomía de calcáneo y 14 (23,3%) con artrodesis. Conclusiones: Al igual que en la serie de Maceira y Rochera, encontramos una mayor prevalencia de EMW entre los nacidos alrededor de la Guerra Civil española y el periodo de movimientos migratorios masivos acontecidos en la quinta década del siglo xx. El tratamiento sigue sin estar bien establecido.(AU)

Background and aim: Müller-Weiss disease (MWD) is a rare anomaly of the tarsal scaphoid. Maceira and Rochera proposed the most commonly accepted etiopathogenic theory, in which dysplastic, mechanical, and socioeconomic environmental factors would be involved. The aim is to describe the clinical and sociodemographic characteristics of patients with MWD in our setting, corroborate their association with the socioeconomic factors previously described, estimate the influence of other factors involved in the development of MWD, and describe the treatment carried out. Materials and methods: Retrospective study of 60 patients diagnosed with MWD in 2 tertiary hospitals of Valencia (Spain) between 2010 and 2021. Results: Sixty patients were included, 21 (35.0%) men and 39 (65.0%) women. In 29 (47.5%) cases, the disease was bilateral. The mean age of onset of symptomatology was 41.9±20.3 years. During childhood, 36 (60.0%) patients suffered migratory movements, and 26 (43.3%) had dental problems. The mean age of onset was 14.6±4.5 years. Thirty-five (58.3%) cases were treated orthopedically versus 25 (41.7%) treated surgically, 11 (18.3%) by calcaneal osteotomy, and 14 (23.3%) with arthrodesis. Conclusions: As in the series of Maceira and Rochera, we found a higher prevalence of MWD among those born around the Spanish Civil War and the period of massive migratory movements that occurred in the fifth decade of the 20th century. Treatment is still not well established.(AU)

[Translated article] Aetiopathogenic factors and treatment of Müller-Weiss disease / Factores etiopatogénicos y tratamiento de la enfermedad de Müller-Weiss

Antecedentes y objetivo: La enfermedad de Müller-Weiss (EMW) es una anomalía poco frecuente del escafoides tarsiano. Maceira y Rochera propusieron la teoría etiopatogénica más comúnmente aceptada, en la que estarían implicados factores displásicos, mecánicos y ambientales socioeconómicos. Se pretende describir las características clínicas y sociodemográficas de los pacientes de nuestro entorno con EMW, corroborar su asociación con los factores socioeconómicos descritos previamente, estimar la influencia de otros factores descritos en el desarrollo de la EMW, así como describir el tratamiento realizado. Materiales y métodos: Estudio retrospectivo de 60 pacientes diagnosticados de EMW en 2 hospitales terciarios de Valencia (España) entre los años 2010 y 2021. Resultados: Se incluyeron 60 pacientes, 21 (35,0%) hombres y 39 (65,0%) mujeres. En 29 (47,5%) casos la afectación fue bilateral. La media de edad de inicio de la sintomatología fue de 41,9±20,3 años. Durante la infancia, 36 (60,0%) pacientes sufrieron movimientos migratorios, y 26 (43,3%) problemas dentarios. La edad media de inicio laboral fue de 14,6±4,5 años. Se trataron de forma ortopédica 35 (58,3%) casos frente a 25 (41,7%) tratados quirúrgicamente, 11 (18,3%) mediante osteotomía de calcáneo y 14 (23,3%) con artrodesis. Conclusiones: Al igual que en la serie de Maceira y Rochera, encontramos una mayor prevalencia de EMW entre los nacidos alrededor de la Guerra Civil española y el periodo de movimientos migratorios masivos acontecidos en la quinta década del siglo xx. El tratamiento sigue sin estar bien establecido.(AU)

Background and aim: Müller-Weiss disease (MWD) is a rare anomaly of the tarsal scaphoid. Maceira and Rochera proposed the most commonly accepted etiopathogenic theory, in which dysplastic, mechanical, and socioeconomic environmental factors would be involved. The aim is to describe the clinical and sociodemographic characteristics of patients with MWD in our setting, corroborate their association with the socioeconomic factors previously described, estimate the influence of other factors involved in the development of MWD, and describe the treatment carried out. Materials and methods: Retrospective study of 60 patients diagnosed with MWD in 2 tertiary hospitals of Valencia (Spain) between 2010 and 2021. Results: Sixty patients were included, 21 (35.0%) men and 39 (65.0%) women. In 29 (47.5%) cases, the disease was bilateral. The mean age of onset of symptomatology was 41.9±20.3 years. During childhood, 36 (60.0%) patients suffered migratory movements, and 26 (43.3%) had dental problems. The mean age of onset was 14.6±4.5 years. Thirty-five (58.3%) cases were treated orthopedically versus 25 (41.7%) treated surgically, 11 (18.3%) by calcaneal osteotomy, and 14 (23.3%) with arthrodesis. Conclusions: As in the series of Maceira and Rochera, we found a higher prevalence of MWD among those born around the Spanish Civil War and the period of massive migratory movements that occurred in the fifth decade of the 20th century. Treatment is still not well established.(AU)

Management of acute lesser toe pain.

Patients with foot pain commonly present to their primary care physicians for their initial management and treatment. These patients and their respective foot or lesser toe pain can present the physician with a complex problem with a long differential list. Depending on the timing of the pain and underlying pathology, these differentials can be divided into acute and acute exacerbation of chronic conditions. This review categorizes the history, physical exam, radiological findings, conservative treatment, and surgical management for each major cause of lesser toe pain, whether acute or chronic. The acute conditions surrounding lesser toe pain in the adult population discussed are toe fractures, toe dislocations, and metatarsal head and neck fractures. The chronic pathologies surrounding lesser toe pain in the adult population evaluated in this review include metatarsalgia, Morton's neuroma, Freiberg infraction, brachymetatarsia, bunionettes, and lesser toe disorders.

Conservative treatment of Freiberg's infraction using foot orthoses: A tale of two prescriptions presented as a case study to open debate.

'Freiberg's infraction or disease' is an osteonecrotic process primarily affecting the 2nd & 3rd metatarsal heads. Early diagnosis is difficult, and the underlying pathogenesis remains unclear. Surgical options for late disease have been widely reported in the literature, yet details on conservative management for the early stages of Freiberg's are largely absent. Pathology should be treated where possible using an evidence-based approach, yet evidence for conservative management in acute stages of Freiberg's is lacking. A case study is presented that outlines two different prescription interventions using foot orthoses; one that attempted to 'offload' the metatarsal head by creating space beneath it; and one that attempted to 'offloaded' by increasing controlled loading of the metatarsals proximal to the head. These resulted in very different outcomes for the patient. The authors will attempt to give a 'pathomechanical rationale' for the treatment outcomes based on mechanical stress principles, and a consequential explanation as to why one type of insole prescription seemed more successful in reducing symptoms and raising activity levels, while another was not.

A Rabbit Model of Osteochondral Regeneration Using Three-Dimensional Printed Polycaprolactone-Hydroxyapatite Scaffolds Coated with Umbilical Cord Blood Mesenchymal Stem Cells and Chondrocytes.

BACKGROUND This study aimed to investigate a rabbit model of osteochondral regeneration using three-dimensional (3-D) printed polycaprolactone-hydroxyapatite (PCL-HA) scaffolds coated with umbilical cord blood mesenchymal stem cells (UCB-MSCs) and chondrocytes. MATERIAL AND METHODS Nine female New Zealand white rabbits were included in the study. The 3-D PCL-HA scaffolds were prepared using fused deposition modeling 3-D printing technology. Seeding cells were prepared by co-culture of rabbit UCB-MSCs and chondrocytes with a ratio of 3: 1. A total of 4×106 cells were seeded on 3-D PCL-HA scaffolds and implanted into rabbits with femoral trochlear defects. After 8 weeks of in vivo implantation, 12 specimens were sampled and examined using histology and scanning electron microscopy (SEM). The International Cartilage Repair Society (ICRS) macroscopic scores and histological results were recorded and compared with those of the unseeded PCL-HA scaffolds. RESULTS Mean ICRS scores for the UCB-MSCs and chondrocyte-seeded PCL-HA scaffolds (group A) were significantly higher than the normal unseeded control (NC) PCL-HA scaffold group (group B) (P<0.05). Histology with safranin-O and fast-green staining showed that the UCB chondrocyte-seeded PCL-HA scaffolds significantly promoted bone and cartilage regeneration. CONCLUSIONS In a rabbit model of osteochondral regeneration using 3-D printed PCL-HA scaffolds, the UCB chondrocyte-seeded PCL-HA scaffold promoted articular cartilage repair when compared with the control or non-seeded PCL-HA scaffolds.

Continuous low-intensity ultrasound attenuates IL-6 and TNFα-induced catabolic effects and repairs chondral fissures in bovine osteochondral explants.

BACKGROUND: Cartilage repair outcomes are compromised in a pro-inflammatory environment; therefore, the mitigation of pro-inflammatory responses is beneficial. Treatment with continuous low-intensity ultrasound (cLIUS) at the resonant frequency of 5 MHz is proposed for the repair of chondral fissures under pro-inflammatory conditions. METHODS: Bovine osteochondral explants, concentrically incised to create chondral fissures, were maintained under cLIUS (14 kPa (5 MHz, 2.5 Vpp), 20 min, 4 times/day) for a period of 28 days in the presence or absence of cytokines, interleukin-6 (IL-6) or tumor necrosis factor (TNF)α. Outcome assessments included histological and immunohistochemical staining of the explants; and the expression of catabolic and anabolic genes by qRT-PCR in bovine chondrocytes. Cell migration was assessed by scratch assays, and by visualizing migrating cells into the hydrogel core of cartilage-hydrogel constructs. RESULTS: Both in the presence and absence of cytokines, higher percent apposition along with closure of fissures were noted in cLIUS-stimulated explants as compared to non-cLIUS-stimulated explants on day 14. On day 28, the percent apposition was not significantly different between unstimulated and cLIUS-stimulated explants exposed to cytokines. As compared to non-cLIUS-stimulated controls, on day 28, cLIUS preserved the distribution of proteoglycans and collagen II in explants despite exposure to cytokines. cLIUS enhanced the cell migration irrespective of cytokine treatment. IL-6 or TNFα-induced increases in MMP13 and ADAMTS4 gene expression was rescued by cLIUS stimulation in chondrocytes. Under cLIUS, TNFα-induced increase in NF-κB expression was suppressed, and the expression of collagen II and TIMP1 genes were upregulated. CONCLUSION: cLIUS repaired chondral fissures, and elicited pro-anabolic and anti-catabolic effects, thus demonstrating the potential of cLIUS in improving cartilage repair outcomes.

Desktop-stereolithography 3D printing of a radially oriented extracellular matrix/mesenchymal stem cell exosome bioink for osteochondral defect regeneration.

Mitochondrial dysfunction and oxidative stress damage are hallmarks of osteoarthritis (OA). Mesenchymal stem cell (MSC)-derived exosomes are important in intercellular mitochondria communication. However, the use of MSC exosomes for regulating mitochondrial function in OA has not been reported. This study aimed to explore the therapeutic effect of MSC exosomes in a three dimensional (3D) printed scaffold for early OA therapeutics. Methods: We first examined the mitochondria-related proteins in normal and OA human cartilage samples and investigated whether MSC exosomes could enhance mitochondrial biogenesis in vitro. We subsequently designed a bio-scaffold for MSC exosomes delivery and fabricated a 3D printed cartilage extracellular matrix (ECM)/gelatin methacrylate (GelMA)/exosome scaffold with radially oriented channels using desktop-stereolithography technology. Finally, the osteochondral defect repair capacity of the 3D printed scaffold was assessed using a rabbit model. Results: The ECM/GelMA/exosome scaffold effectively restored chondrocyte mitochondrial dysfunction, enhanced chondrocyte migration, and polarized the synovial macrophage response toward an M2 phenotype. The 3D printed scaffold significantly facilitated the cartilage regeneration in the animal model. Conclusion: This study demonstrated that the 3D printed, radially oriented ECM/GelMA/exosome scaffold could be a promising strategy for early OA treatment.

Freiberg Disease and Avascular Necrosis of the Metatarsal Heads.

Freiberg disease is characterized as osteochondrosis of the second metatarsal head. It is the fourth most common form of primary osteochondrosis with a significant predilection to the adolescent athletic female population, although it has been seen over a wide age range. If treated early, osteochondroses such as Freiberg disease are essentially self-limiting, often resolving with nonoperative management. When surgery is warranted, it is imperative the patient's age, activity level, and degree of articular deformity be taken into account.

The Subchondral Bone Is Affected by Bone Marrow Stimulation: A Systematic Review of Preclinical Animal Studies.

OBJECTIVE: Despite the mechanical and biological roles of subchondral bone (SCB) in articular cartilage health, there remains no consensus on the postoperative morphological status of SCB following bone marrow stimulation (BMS). The purpose of this systematic review was to clarify the morphology of SCB following BMS in preclinical, translational animal models. DESIGN: The MEDLINE and EMBASE databases were systematically reviewed using specific search terms on April 19, 2016 based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The morphology of the SCB was assessed using of microcomputed tomography (bone density) and histology (microscopic architecture). RESULTS: Seventeen animal studies with 520 chondral lesions were included. The morphology of SCB did not recover following BMS. Compared with untreated chondral defects, BMS resulted in superior morphology of superficial SCB and cartilage but inferior morphology (specifically bone density, P < 0.05) of the deep SCB. Overall, the use of biological adjuvants during BMS resulted in the superior postoperative morphology of SCB. CONCLUSIONS: Alterations in the SCB following BMS were confirmed. Biologics adjuvants may improve the postoperative morphology of both SCB and articular cartilage. Refinements of BMS techniques should incorporate consideration of SCB damage and restoration. Investigations to optimize BMS techniques incorporating both minimally invasive approaches and biologically augmented platforms are further warranted.

Healing of Osteochondral Defects via Endochondral Ossification in an Ovine Model.

OBJECTIVE: The objective of this study was to describe the mechanism of healing of osteochondral defects of the distal femur in the sheep, a commonly used translational model. Information on the healing mechanism be useful to inform the design of tissue engineering devices for joint surface defect repair. DESIGN: A retrospective study was conducted examining 7-mm diameter osteochondral defects made in the distal medial femoral condyle of 40 adult female sheep, comprising control animals from 3 separate structures. The healing of the defects was studied at post mortem at up to 26 weeks. RESULTS: Osteochondral defects of the distal femur of the sheep heal through endochondral ossification as evidenced by chondrocyte hypertrophy and type X collagen expression. Neocartilage is first formed adjacent to damaged cartilage and then streams over the damaged underlying bone before filling the defect from the base upward. No intramembranous ossification or isolated mesenchymal stem cell aggregates were detected in the healing tissue. No osseous hypertrophy was detected in the defects. CONCLUSIONS: Osteochondral defects of the medial femoral condyle of the sheep heal via endochondral ossification, with neocartilage first appearing adjacent to damaged cartilage. Unlike the mechanism of healing in fracture repair, neocartilage is eventually formed directly onto damaged bone. There was most variability between animals between 8 and 12 weeks postsurgery. These results should be considered when designing devices to promote defect healing.

Role of Mesenchymal Stem Cells Densities When Injected as Suspension in Joints with Osteochondral Defects.

OBJECTIVE: The aim of this study was to evaluate an intraarticular injection of different doses of autologous mesenchymal stem cells (MSCs) for improving repair of midterm osteochondral defect. DESIGN: At 4 weeks postoperative marrow stimulation model bilaterally (3 mm diameter; 4 mm depth) in the medial femoral condyle, autologous MSCs were injected into knee joint. Twenty-four Japanese rabbits aged 6 months were divided randomly into 4 groups ( n = 6 per group): the control group and and MSC groups including 0.125, 1.25, and 6.25 million MSCs. Repaired tissue was assessed macroscopically and histologically at 4 and 12 weeks after intraarticular injection of MSCs. RESULTS: At 12 weeks, there was no repair tissue in the control group. The gross appearance of the 1.25 and 6.25 million MSC groups revealed complete repair of the defect with white to pink tissue at 12 weeks. An osteochondral repair was histologically significantly better in the 1.25 and 6.25 million MSC groups than in the control and 0.125 million MSC groups at 4 and 12 weeks, due to presence of hyaline-like tissue in the deep layer at 4 weeks, and at 12 weeks hyaline cartilage formation at the periphery and fibrous tissue containing some chondrocytes in the deep layer of the center of the defect. Subchondral bone was restructured in the 1.25 and 6.25 million MSC groups, although it did not resemble the normal bone. CONCLUSION: An intraarticular injection of 1.25 or 6.25 million MSCs could promote the repair of subchondral bone, even in the case of midterm osteochondral defect.

Joint debridement and microfracture for treatment late-stage Freiberg-Kohler's disease: Long-term follow-up study.

BACKGROUND: Freiberg-Kohler's disease is not a common disease and although various reports have been described since 1914, treatment methods are not completely established. The purpose of the present retrospective study was to evaluate the long-term outcomes following joint debridement and microfracture procedures for the treatment of Freiberg-Kohler's disease. METHODS: Fifteen consecutive patients (16 feet) with Freiberg-Kohler's disease (Smillie's classification grade III-V) were operated between May 1996 to December 2011. All patients followed the same post-operative protocol. The objective and subjective evaluations were taken at the initial examination and at final follow-up. RESULTS: Mean follow-up was 11 years ±5.5 (range 4.2-19.7 years). The AOFAS score, VAS score and ROM of the MTP joint improved significantly after surgery (p value <0.05). The AOFAS score improved from a preoperative value of 46.7±15.5 points to 83.2±9.4 points postoperative (p<0.05). The mean preoperative joint ROM was 28°±8° and 49°±13° postoperative (p<0.05). VAS score improved from a preoperative value of 5.5±1.2 points to 1.2±1 points at last follow-up (p<0.05). At the end of follow-up 13 patients (81%) declared they were very satisfied, 3 patients (19%) satisfied and nobody unsatisfied. CONCLUSIONS: Our results suggest that joint debridement and microfracture procedure is an effective surgical treatment for late-stage Freiberg-Kohler's disease with decrease of daily pain, improved ROM, and high patient satisfaction.

Osteochondral lesions of the talus.

Background and purpose - The frequency of progression of osteoarthritis and persistence of symptoms in untreated osteochondral lesion of the talus (OCL) is not well known. We report the outcome of a nonoperative treatment for symptomatic OCL. Patients and methods - This study included 142 patients with OCLs from 2003 to 2013. The patients did not undergo immobilization and had no restrictions of physical activities. The mean follow-up time was 6 (3-10) years. Initial MRI and CT confirmed OCL and showed lesion size, location, and stage of the lesion. Progression of osteoarthritis was evaluated by standing radiographs. In 83 patients, CT was performed at the final follow-up for analyses of the lesion size. We surveyed patients for limitations of sports activity, and Visual Analogue Scales (VAS), AOFAS, and SF-36 were assessed. Results - No patients had progression of osteoarthritis. The lesion size as determined by CT did not change in 69/83 patients, decreased in 5, and increased in 9. The mean VAS score of the 142 patients decreased from 3.8 to 0.9 (p < 0.001), the mean AOFAS ankle-hindfoot score increased from 86 to 93 (p < 0.001), and the mean SF-36 score increased from 52 to 72 (p < 0.001). Only 9 patients reported limitations of sports activity. The size and location of the lesion did not correlate with any of the outcome scores. Interpretation - Nonoperative treatment can be considered a good option for patients with OCL.

Bioactive Scaffolds for Regeneration of Cartilage and Subchondral Bone Interface.

The cartilage lesion resulting from osteoarthritis (OA) always extends into subchondral bone. It is of great importance for simultaneous regeneration of two tissues of cartilage and subchondral bone. 3D-printed Sr5(PO4)2SiO4 (SPS) bioactive ceramic scaffolds may achieve the aim of regenerating both of cartilage and subchondral bone. We hypothesized that strontium (Sr) and silicon (Si) ions released from SPS scaffolds play a crucial role in osteochondral defect reconstruction. Methods: SPS bioactive ceramic scaffolds were fabricated by a 3D-printing method. The SEM and ICPAES were used to investigate the physicochemical properties of SPS scaffolds. The proliferation and maturation of rabbit chondrocytes stimulated by SPS bioactive ceramics were measured in vitro. The stimulatory effect of SPS scaffolds for cartilage and subchondral bone regeneration was investigated in vivo. Results: SPS scaffolds significantly stimulated chondrocyte proliferation, and SPS extracts distinctly enhanced the maturation of chondrocytes and preserved chondrocytes from OA. SPS scaffolds markedly promoted the regeneration of osteochondral defects. The complex interface microstructure between cartilage and subchondral bone was obviously reconstructed. The underlying mechanism may be related to Sr and Si ions stimulating cartilage regeneration by activating HIF pathway and promoting subchondral bone reconstruction through activating Wnt pathway, as well as preserving chondrocytes from OA via inducing autophagy and inhibiting hedgehog pathway. Conclusion: Our findings suggest that SPS scaffolds can help osteochondral defect reconstruction and well reconstruct the complex interface between cartilage and subchondral bone, which represents a promising strategy for osteochondral defect regeneration.

More than 40 years' follow-up of an unconstrained metal lunate replacement for the treatment of Kienböck's disease.

Kienböck's disease is characterised by avascular necrosis of the lunate bone, and over the years it has been a challenging disease to manage, with differing opinions on the best intervention. We present an interesting case of a metallic unconstrained lunate replacement that is still functioning well in a patient 40 years after surgery. This case report represents the longest follow-up of any such prosthesis.

Pediatric Osteochondral Lesions.

Osteochondral lesions are common in children and may arise from a variety of etiologies. Although they most frequently occur in the knee, other joints may be involved including the ankle and elbow. We describe the typical imaging appearance of osteochondral lesions with a focus on radiographs and magnetic resonance imaging. Assessment of the stability of these lesions is of paramount importance in directing management. As such, we describe staging schemes as well as imaging features differentiating stable from unstable lesions. Finally, we briefly discuss management strategies as they correlate to imaging findings.

Treatment of Freiberg Disease.

Freiberg disease, or osteochondrosis of the lesser metatarsal head, usually involves the second metatarsal and presents during the second or third decades of life. Conservative measures to relieve pressure on the affected metatarsal head are the first-line treatments, with good success for Smillie stage I to III disease. Operative treatments are divided into joint-preserving and joint-reconstructing procedures. Although multiple case series describe success with numerous techniques, there are no established guidelines for treatment. All surgical techniques carry a risk of a stiff or floating toe and transfer metatarsalgia. This article reviews the current surgical treatment options for Freiberg disease.

Patient-Reported Outcomes Following Platelet-Rich Plasma Injections in Treating Osteochondral Lesions of the Talus: A Critically Appraised Topic.

Clinical Scenario: Osteochondral lesions (OCLs) of the talus can result from ankle sprains which are the most common injury in the physically active. Recently, platelet-rich plasma (PRP) has been used to develop an innovate treatment for OCLs of the talus. CLINICAL QUESTION: Do PRP injections improve self-reported pain and ankle function in patients with OCL of the talus? Summary of Key Findings: 3 randomized controlled trials were included. One of the studies compared a single dose of PRP to a single dose of hyaluronic acid (HA) or saline when added as an adjunct to microfracture surgery. Another study compared a group receiving a single dose of PRP after microfracture surgery to a group that only received microfracture surgery. The last study compared a series of 3 PRP injections to a series of 3 HA injections. In all 3 studies PRP appeared to be more effective in pain and function outcomes than comparison treatments. The superior outcomes of PRP were demonstrated at times as short as 4 weeks and as long as 25 months. Clinical Bottom Line: There is moderate to strong evidence that PRP produces favorable, short-term, pain and function results compared to HA, saline, and/or microfracture surgery alone. Strength of Recommendation: Level 2.