Comparison Of Two Posterior Soft-tissue Repair Techniques To Prevent Dislocation After Total Hip Arthroplasty Using A Posterolateral Approach

Background: Posterior soft-tissue repair has been considered to be an effective measure to dwindle the early dislocation rate after total hip arthroplasty by the posterolateral approach.Precious documents reported several techniques including through-tendon repair,through-bone repair and through-anchor repair.Through-anchor repair was seldom performed by orthopedists,because the cost of this technique is much higher than other repair techniques.Through-tendon repair and through-bone repair were most commonly used.However,few relevant contrast researches of them can be found in previous literatures.Orthopedists still reach no consensus on the best repair method of posterior soft-tissue.The aim of this study was to give contrast analysis of the two techniques in terms of the clinical availability and safety to determine whether through-bone repair is superior to through-tendon repair,and to give more evidence-based references for orthopedists in selecting posterior soft-tissue repair techniques in total hip arthroplasty.Material/Methods: 87 patients who underwent posterior soft-tissue repair in total hip arthroplasty by the posterolateral approach were retrospectively enrolled in this study after evaluation of clinical and follow-up data.The included patients were divided into two groups according to the repair methods of the posterior soft-tissue.46 patients in through-bone repair group and 41 patients in through-tendon repair group.In case of through-bone repair,two 2 mm drill holes were placed 2 cm apart in the trochanteric crest of the greater trochanter.And then,two pieces of absorbable 4-0-Vicryls were threaded through each drill hole,one was knotted tightly with the suture reserved in the posterior capsule,and another was tied with the suture on the piriformis or conjoined tendon.The reconstruction of posterior soft-tissue was completed.In case of through-tendon repair,the posterior capsule and external rotators were repaired with absorbable 4-0-Vicryls through two suture sites 1-1.5 cm apart in the posterior border of gluteus medius tendon.The lower suture site was as close to the attachment of gluteus medius tendon on the greater trochanter.The remaining process was similar to through-bone repair technique.Postoperative preventive measures of dislocation after surgery were performed in all patients for 4 weeks.The primary evaluation indexes included the early dislocation rate and repair-related complications.The secondary evaluation indexes included postoperative pain(VAS at 1 week,1 month and 6 months postoperatively)(visual analog pain scale,VAS),hip function(HHS at 1 month and 6months postoperatively)(hip harris scale,HHS),patient satisfaction and operation related indexes including operating time,intraoperative blood loss and volume of drainage in the first 24 hours after surgery.Results: All patients were followed at least for six months.There was only one case of dislocation from through-tendon repair group occurring three weeks after surgery,resulting in an overall dislocation rate of 1.1%.The discrepancy in early dislocation rate between through-bone repair and through-tendon repair group was not statistically significant(2.4%vs0%,p=0.471).No patient sustained the complications relevant to repair techniques in this study.Compared with preoperative outcomes,all patients in each group obtained significantly lower pain scores after surgery.The pain scores in through-bone repair group were significantly lower than that of in through-tendon repair group one week(4.93vs5.68,p=0.026)and one month(1.72vs1.99,P=0.038)after surgery.There was no statistically significant difference in pain scores six months after surgery between the two groups(p=0.891).Harris scores of all patients after surgery were significantly higher compared with the preoperative results(All p<0.05).No statistically significant discrepancy was found when comparing Harris scores between the two groups at the same period(All p>0.05).Furthermore,the operation related indexes were not significantly different between the two groups except for the volume of drainage in the first 24 hours after surgery(229.46mlvs172.07 ml,p=0.013).Patients satisfaction of through-bone repair group was significantly higher than through-tendon repair group(p=0.025).Conclusions: Both through-bone and through-tendon repair technique are relatively safe and efficient repair methods.Although no statistical discrepancy in early dislocation between them was observed in this study,the early pain scores and patient satisfaction supported through-bone repair technique.Besides,there was no more additional medical cost and operating time associated with through-bone repair technique compared with through-tendon repair technique.If through-tendon repair technique is regarded as the standard of comparison,through-bone repair technique tends to be a potentially cost-effective technique.Hence we intensively recommend that through-bone repair technique should be chosen firstly by orthopedists when performing the reconstruction of the posterior soft-tissue in THA by a posterolateral approach.