Tissue-repair Effect Of Combined Arthroscopic Segmental Labral Debridement With Microfracture For Irreparable Labral Tear

Background: Acetabular labral tear is most secondary to FAI which is featured by either femoral or acetabular anatomic abnormality.With the loss of seal effect caused by labral tear,cartilage lesions may be induced by the mechanisms of the absence of efficient synovial fluid friction and physiological stress environment of hip.As for irreparable labral tear,the general surgical option is to resect the unstable torn labrum for alleviating pain in the early stage,which,in the long term,might cause cartilage lesions and even severe OA requiring arthroplasty.Recently,few researches have advocated labral reconstruction using autograft like iliotibial band,which so far is premature and in need of improvement.Meanwhile,its complexity and highly demanded surgical skill obstructs widespread application of the surgical option.The combined arthroscopic segmental labral debridement and marrow stimulation is able to regenerate the larum-like tissue as well as restore the seal effect of torn labrum.Accordingly,we have compared the outcomes of combined arthroscopic segmental labral debridement and microfracture at the acetabular rim to that of labral debridement alone arthroscopically and analyzed the possibility of the proposed surgical option.Objective: To compare the outcomes of the combined arthroscopic segmental labral debridement and microfracture at the acetabular rim to that of labral debridement alone arthroscopically aiming to figure out the effect of marrow stimulation on the restoration of morphology and function of acetabular labrum.Methods: From February 2014 to November 2017,43patients(53 hips)undergoing hip arthroscopy for labral injury were eligible.The included patients were divided into three groups: microfracture group,resection group and selective debridement group.Radiographically,single radial hip MRI and fluoroscopic image of the involved hip under distraction were obtained in patients of microfracture and resection group at least 0.5 years postoperatively and the results were compared between two groups.Single radial hip MRI were performed to observe the existence of homogeneous low signal at the relative area and fluoroscopic image of the involved hip under distraction were used to exam the restoration of seal effect.In terms of functional outcomes,HHS,VAS,HOS-ADL and HOS-SSS scores were obtained preoperatively and postoperatively for the assessment of functional outcome.Meanwhile,muscular strength around hip joint was measured through portable dynamometer.Results: The mean follow-up was 33.7±15.9 months(range,7-62 months)and average age was 40.0±10.4 years(range,19-61 years).There were 22 males(29 hips)and 21 females(24hips).The microfracture group consisted of 7 males(8 hips)and 11 female(13 hips)and the location of labral tear included 1 anterior,3 superior and 14 anterosuperior.The resection group consisted of 6 males(8 hips)and 6 females(6 hips)and the location of labral tear included 1 anterior and 11 anterosuperior.The selective group consisted of 9 males(13 hips)and 4 females(5 hips)and the location of labral tear included 1 anterior,1 superior and 12 anterosuperior.Single radial hip MRI demonstrated homogeneous low signal intensity located at the relative area where the labrum was deemed irreparable and resected followed by microfracture performing at the remaining acetabular rim in all patients of the microfracture group.Meanwhile,result was opposite at the d efect of acetabular rim where injured labrum was simply resected in the resection group.Furthermore,vacuum effect was apparent in all fluoroscopic view of patients from microfracture group whereas vacuum effect was observed in half of patients from the resection group.With regard to functional assessment of hip joint,three groups showed significant increase in postoperative HHS,VAS,HOS-ADL and HOS-SSS compared with preoperative scores(P<0.05).There demonstrates no statistically significant difference of the postoperative HHS,VAS,HOS-ADL and HOS-SSS among the three groups(P>0.05)despite the fact that microfracture and resection groups had a lower HHS,HOS-ADL and HOS-SSS compared with selective group(P<0.05).Furthermore,no statistical difference was found in VAS among the three groups and the muscular strength of the involved hip to that of the uninvolved one in the 3 groups were similar(P>0.05).Conclusion:(1)Extra marrow stimulation is able to recreate the fibrocartilage-like tissue at the labrum-defect area of the acetabular rim and restore the hydraulic suction environment compared with labral debridement alone.(2)Labral debridement with or without microfracture at the rim of acetabulum have achieved the similar short and moderate-term outcomes to that of selective labral debridement.(3)Due to the morphological and functional restoration of the torn labrum,the combined arthroscopic labral debridement and microfracture at the rim of acetabulum is hopefully able to maintain a functional hip in the long term while alleviate the symptom in the early phase,which provides a new treatment option for irreparable labral lesions.