Compared learning curves of the direct anterior and anterolateral approach for minimally invasive hip replacement.

Minimally invasive hip arthroplasty becomes increasingly popular. It is technically challenging and the approaches used are associated with a considerable learning curve. This nurtures concerns regarding patient safety, surgical training, and cost effectiveness. Consequently, we initiated a study comparing the learning curves of a supervised trainee surgeon utilizing both the anterolateral and direct anterior approach (DAA) when introduced to minimally invasive hip replacement surgery. Outcome measurements included the Harris hip score (HHS), cup inclination and anteversion, offset and leg length, stem placement, surgical time and complications. Time from incision to suture decreased significantly over time but did not differ between both groups. The functional outcomes (HHS) after six weeks and three months were comparable (p=0.069 and 0.557) and within the expected range equalling 90.3 (anterior) and 89.2 (anterolateral) points. With both approaches safe component placement was readily achieved. Both offset and leg length, however, were reconstructed more reliably with the DAA (p=0.02 and 0.001). A higher rate of dislocations was seen with the anterior, more perioperative infections with the anterolateral approach. We suggest that supervision by an experienced surgeon favourably influences the learning curves for both the minimally invasive DAA and anterolateral approach and conclude that the greatest improvement is seen within the first 60 cases.

A prospective randomized comparison of the minimally invasive direct anterior and the transgluteal approach for primary total hip arthroplasty.

BACKGROUND: The presented prospective randomized controlled single-centre study compares the clinical outcome up to 12 months after total hip arthroplasty using a minimally invasive single-incision direct anterior (DAA) and a direct transgluteal lateral approach. METHODS: A total of 123 arthroplasties were evaluated utilizing the Harris Hip Score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey, a Stepwatch™ Activity Monitor (SAM), and a timed 25 m foot walk (T25-FW). Postoperative x-ray images after THA were reviewed to determine inclination and stem positioning. RESULTS: At final follow-up, the XSFMA functional index scores were 10.3 (anterior) and 15.08 (lateral) while the bother index summed up to a score of 15.8 (anterior) and 21.66 (lateral) respectively, thus only differing significantly for the functional index (p = 0.040 and p = 0.056). The SF-36 physical component score (PCS) was 47.49 (anterior) and 42.91 (lateral) while the mental component score (MCS) summed up to 55.0 (anterior) and 56.23 (lateral) with a significant difference evident for the PCS (p = 0.017; p = 0.714). Patients undergoing THA through a DAA undertook a mean of 6402 cycles per day while those who had undergone THA through a transgluteal approach undertook a mean of 5340 cycles per day (p = 0.012). Furthermore, the obtained outcome for the T25-FW with 18.4 s (anterior) and 19.75 s (lateral) and the maximum walking distance (5932 m and 5125 m) differed significantly (p = 0.046 and p = 0.045). The average HHS showed no significant difference equaling 92.4 points in the anterior group and 91.43 in the lateral group (p = 0.477). The radiographic analysis revealed an average cup inclination of 38.6° (anterior) and 40.28° (lateral) without signs of migration. CONCLUSION: In summary, our outcomes show that after 1 year THA through the direct anterior approach results in a higher patient activity compared to THA utilizing a transgluteal lateral approach while no differences regarding hip function are evident. TRIAL REGISTRATION: DRKS00014808 (German Clinical Trial Register DRKS); date of registration: 31.05.2018.

Function and activity after minimally invasive total hip arthroplasty compared to a healthy population.

PURPOSE: The aim of the present study was to compare the daily activity and functionality in a patient cohort 12 months after total hip arthroplasty (THA) using a direct anterior approach with a healthy non-operated control population. METHODS: Sixty-four patients who underwent THA and 59 healthy individuals (control) were assessed regarding their daily activity and joint functionality utilizing the Harris hip score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey and a Stepwatch™ Activity Monitor (SAM). Post-operative x-ray images after THA were analysed regarding inclination and stem positioning. RESULTS: Twelve months after surgery, the average HHS showed no significant difference between both groups equalling 90.7 points in the THA patient group and 90.8 in the healthy volunteer group. The XSFMA functional index scores were 11.0 (THA) and 5.0 (control) while the bother index summed up to a score of 15.3 (THA) and 7.6 (control) respectively thus differing significantly (p < 0.001). Daily activity equalled 4227 (THA) and 4687 (control) load cycles per day (p = 0.327) while a number of 5658 (THA) and 6417 (control) steps per day (p = 0.011) was recorded. The SF-36 physical component scores were 47.3 (THA) and 50.6 (control) points while the psychometric properties added up to a score of 56.1 (THA) and 55.9 (control). The physical component was determined to be significantly different (p < 0.001) whereas no statistically significant difference could be shown for the psychometric properties (p = 0.511). The radiographic analysis revealed an average cup inclination of 39.9° without signs of migration. Stem positioning was neutral in 53% of all cases while 36% were graded varus and 11% valgus. CONCLUSION: In summary, our short-term results show an activity, functionality and quality of life for patients one year after THA comparable to healthy control individuals.