Effect Of Arthroscopic Microfracture On Osteochondral Lesion Of The Talus And Shock Wave On Bone Marrow Edema Syndrome Of The Foot

Background: Articular cartilage lesion is one of the most common types of injury in orthopedic surgery.Since the spontaneous repair ability of cartilage is limited after traumatic injury or degenerative joint disease,the treatment of cartilage lesion is still challenging.In the past decade,many surgical procedures have been developed to promote long-lasting repairs.These methods are arthroscopic or open surgical techniques,including Bone-Marrow Stimulation(BMS),such as drilling and microfracture,osteochondral transplantation,periosteum or cartilage transplantation,as well as cell transplantation,such as autologous chondrocyte transplantation.Due to lack of larger-scale comparative experiments and long-term results,the relative advantages of these methods are still controversial.Osteochondral lesions of the talus(OLT)is one of the main factors leading to chronic ankle pain,and various surgical strategies have been developed for its treatment.With the development of orthopedic arthroscopy technology,ankle arthroscopic debridement and microfractures have become the main surgical methods for OLT,especially for osteochondral defects with an area less than 150mm~2 or a diameter less than 15 mm.However,most studies on treating OLT with arthroscopic microfractures focused on the improvement of early symptoms and functions,little has been known about its change in imaging results after surgical treatment.Recent years,the development of cartilage repair technology has brought new interest in the treatment of cartilage lesion,which have led to an increased demand for an accurate,reproducible,ideal,and noninvasive imaging method for assessing cartilage lesion,both for the primary diagnosis and for subsequent follow-ups after surgical treatment.The purpose of cartilage imaging is to visualize the cartilage surface,its matrix thickness,volume and the subchondral boundary.Magnetic resonance imaging(MRI)is the standard imaging method for cartilage imaging.It is very useful for assessing the morphological state of cartilage defects and repaired tissues after surgery.Bone marrow edema(BME)signal could be observed in the affected cartilage of most OLT patients on MRI.However,the significance of BME and its impact on clinical efficacy are still unclear.In this paper,we retrospectively analyzed and compared the clinical efficacy and MRI evaluation efficacy of arthroscopic microfracture for OLT.Bone Marrow Edema Syndrome(BMES)is a rare and self-limiting disease,which is characterized by sudden or gradual swelling and pain during rest or activity without a definite cause such as trauma,and its pathogenesis is unclear.The incidence of BMES in the foot is relatively low.It is mainly manifested as foot pain,swelling and limited activity.It can suddenly or slowly attack during rest,activity and night,and the severity of pain and swelling can gradually increase.BMES usually improves gradually within 3 to 9 months.Severe lesions may progress to osteonecrosis or a reversible form of osteonecrosis.The goal of treating BMES is to relieve pain and shorten the clinical course.Non-surgical treatments of symptomatic BME include non-weight-bearing or partial weight-bearing,walking boots,non-steroidal anti-inflammatory drugs,bisphosphonates,calcium channel blockers,and prostaglandin synthesis inhibitors(such as iloprost),physiotherapy,relaxation therapy and massage therapy.However,these methods may not be accepted by athletes or people who need faster pain relief and function improvement.Therefore,there is an urgent need to find new treatment techniques to improve the efficacy and shorten the development process of the disease.Extracorporeal shock wave therapy(ESWT)has gradually gained popularity in the field of orthopedics and has shown good analgesic effects and therapeutic value for some chronic sports injuries.Today,although the exact mechanism of action of ESWT is still unknown,some reports have shown that good or even excellent results can be obtained with ESWT,and that this type of treatment activates many necessary cell processes for new blood vessel formation,tissue regeneration,and anti-inflammatory pathways,thus promoting the process of bone repairing.In addition,BME usually shows no obvious abnormalities in X-ray examination,whereas in MRI examination,subtle decrease of regional bone marrow signal intensity can be seen on T1-weighted image,and corresponding increase of signal intensity in focal ischemic infarction or the bone edema area can be seen on T2-weighted image.To this end,we retrospectively analyzed the MRI data of ESWT in the treatment of foot BMES patients,and explored the effectiveness and safety of ESWT in the treatment of foot BMES.Objective: 1.To explore the clinical efficacy and MRI evaluation efficiency of arthroscopic microfracture treatment for OLT.2.To preliminary explore the effectiveness and safety of ESWT in treating foot BMES.Methods: 1.Effect of arthroscopic microfracture on OLT A total of 40 patients diagnosed with OLT and treated with arthroscopic microfractures at the Center for Joint Surgery,Southwest Hospital from January 2016 to May 2019 were included.The primary outcome measure before and after treatment was the area of talus BME under the fat suppression sequence sagittal MRI,and the secondary measures were Visual Analogue Scale(VAS)pain score and American Orthopedic Foot and Ankle Society(AOFAS)score.For statistical analysis,P<0.05 was considered significant difference.2.Effect of ESWT on BMES of the foot Patients who were diagnosed with foot BMES and treated with ESWT for 1-2 courses in the outpatient department at our Center from January 1,2014 to November 30,2018 were followed.The target of ESWT was the most obvious part of foot tenderness,or the most obvious part of bone edema revealed by MRI.One course of ESWT: 1 time/week,5 times in total;shock wave energy flow density was 0.18 m J/mm~2.After one course of treatment,patients took rest for 1 month.If the patient still had obvious local pain,one more course of ESWT was applied.The Visual Analogue Scale(VAS)score and the Ankle-Hindfoot Score of the American Academy of Foot and Ankle Surgery(AOFAS)were recorded before treatment,3 months after treatment,and at the last follow-up;MRI examinations were done to record the bone edema area in the fat suppression image before treatment and at the last follow-up;the complications during treatment were also recorded.3.All data were processed using SPSS software Statistical analysis was applied on patients’ follow-up results and imaging results.Measurement data were expressed as mean ± standard deviation,and count data were expressed as n(%);measurement data was first tested for normal distribution,data conforming to normal distribution was compared by t test,and data not conforming to normal distribution was compared by Wilcoxon Rank sum test;the correlation between clinical results and influencing results adopted Spearman correlation coefficient.P<0.05 showed the difference was statistically significant.Results: 1.Effect of arthroscopic microfracture on OLT 1)The 40 patients included were all followed,including 21 males(52.5%)and 19 females(47.5%);Body mass index(BMI): thin(≤18.5),0 cases(0%),normal(>18.5 and <25.0),24 cases(60%),overweight(≥25.0 and <30),11 cases(27.5%),obese(≥30.0),5 cases(12.5%);left ankle,20 cases(50%),right ankle,20 cases(50%);medial lesion,34 cases(85%),lateral lesion,6 cases(15%);27 cases with a history of obvious trauma(67.5%),of which 21 cases(77.8%)had lesions located on the medial side and 6 cases(22.2%)on the lateral side;13 cases(32.5%)had no obvious cause of disease;the duration of symptoms was(28.9±32.1)months(4-138 months).2)During the follow-ups,no complications such as wound infection,deep vein thrombosis of the lower extremities,and vascular and nerve structures related to arthroscopic portals were observed.At the last follow-up,the VAS score decreased from(5.95±1.08)points before surgery to(1.15±1.08)points(P<0.01);the AOFAS score increased from(64.70±9.74)points before surgery to(92.33±5.89)points(P<0.01);7 cases were cured,23 cases were markedly effective,7 cases were effective,and 3 cases were ineffective.The overall effective rate was 92.5%.The maximum area of BME signal on the sagittal MRI was reduced from(80.51±39.55)mm~2 before surgery to(35.41±45.27)mm~2(P<0.01).The maximum area of BME on MRI was not significantly correlated with VAS score(P=0.267,r=1.80);it was not significantly correlated with AOFAS score(P=0.977,r =0.005);the VAS score and AOFAS score were significantly correlated(P<0.01,r=-0.789).2.Effect of ESWT on BMES of the foot 1)A total of 20 patients were followed,including 6 males(30%)and 14 females(70%),aged 49.6±11.8(27-67 years old).There were 10 cases(50%)with BME located in the cuneiform,4 cases(20%)in the calcaneus,3 cases(15%)in the navicular bone,and 3 cases(15%)in the metatarsal bone.Seventeen patients(85%)received 1 course of treatment,and 3 patients(15%)received 2 courses of treatment.2)Compared with before treatment,the patients showed significant improvement in all indicators after 3 months of treatment.The VAS score decreased from 7.75±0.72 to 2.40±0.75(P<0.01);AOFAS score increased from 62.10±7.32 to 82.80± 3.69(P<0.01);at the last follow-up,the VAS score decreased from 2.40±0.75 to 0.70±0.66(P<0.01);the AOFAS score increased from 82.80±3.69 to 93.15±5.11(P<0.01).Sagittal view MRI showed that the BME area was reduced from 132.13±111.10 mm~2 to 41.46±52.24mm~2(P<0.01).Two patients(10%)developed transient erythema on the skin after treatment,which alleviated after 2 days of rest.No serious complications such as infection,vascular nerve injury,and skin necrosis were found in all patients during the treatment.In addition,no complications of osteonecrosis such as bone collapse and joint deformation were observed during the entire follow-up period.Conclusion: 1.In the treatment of OLT with arthroscopic microfractures,the BME signal on MRI in the early stage is significantly reduced compared with before treatment,and as the pain is reduced,the ankle joint function is improved.MRI results are not significantly correlated with the clinical results.Persistent subchondral bone marrow edema may be pathological,indicating recurrence or deterioration of the disease.2.For patients with foot BMES,the application of ESWT can effectively relieve local pain,thereby improving the motor function of the foot and ankle.For some patients,two courses of treatment may be required.This study preliminarily indicates that ESWT is safer with fewer side effects,which is worthy of further study.